Celestial Journeys

Galileoscope - Plastic vs Glass Lenses

2009-08-01T18:06:00.004Z

A day and a half ago I made my first lunar observations with the Galileoscope. I took that opportunity to also experiment with eyepieces.

The Galileoscope's eyepiece and barlow lenses are all made of uncoated plastic. From a cost point of view the decision to make them so was a good one. A single eyepiece with coated glass lenses tends to cost substantially more than the whole Galileoscope kit.

I had noted in an earlier post that glare, or scattered light, was evident when observing Jupiter. When I observed the moon the glare was once again evident. As with Jupiter, at 25x the glare was confined to the region around the limb of the bright object (in this case, the moon).

When I used more costly eyepieces with coated glass lenses the views of the moon became very sharp, contrasty, and glare-free. Yet, the view with the Galileoscope's plastic lenses (at 25x) wasn't too terribly worse. The moon itself looked very similar, virtually identical except for the glare around the lunar limb.

At 50x using a quality eyepiece composed of coated glass lenses the moon was very sharp, contrasty, crisp, and glare-free. But the finest detail visible with the quality eyepiece became very difficult or even impossible to see with the Galileoscope's stock eyepiece and barlow. The moon appeared 'washed out' with the plastic lenses. Nevertheless, one could still see more lunar detail at 50x than at 25x with the plastic lenses.

What about the Galileoscope's glass, achromatic objective? The eyepiece experimentation revealed that the objective is capable of producing very sharp, contrasty images. I was impressed by the quality of the objective, but at magnifications greater than 25x one needs to use higher quality eyepieces to make the most of what the objective has to offer.

On the same night I made observations of Jupiter, Neptune and Uranus with the Galileoscope. The latter two looked indistinguisable from stars. Nevertheless it was a pleasure to see them with the Galileoscope.

While observing the moon and trying out different eyepieces I noticed that an occultation of a star was going to take place. I observed the occultation using the Galileoscope with a far more expensive 7mm Nagler eyepiece. Of course, the occultation could have been observed with the Galileoscope's own eyepiece with or without the barlow. It was with the stock, 25x eyepiece that I became aware that an occultation was imminent.

Size is Relative

2009-07-28T15:47:00.005Z

Is the 47mm clear objective Galileoscope a small telescope or a large telescope? Is it a serious telescope or a toy? The answer depends on one's attitude.

For starters, Galileo revolutionized astronomy with the insights provided by telescopes that were inferior in capability to the Galileoscope pictured above. With a serious attitude of inquiry others can follow in Galileo's footsteps while using a telescope (the Galileoscope) that Galileo would have treasured. To Galileo, the Galileoscope would be a large, high quality telescope -- and indeed it is -- until one starts comparing it with larger and better telescopes.

Don't be fooled! The Galileoscope will not show things as well as the pictures you've seen taken through the vastly more expensive Hubble Space Telescope. After all, if a $15.00 telescope could do as well as Hubble, what would be the point of building and putting into orbit such a large and costly beast?

Many telescopes are marketed by displaying sharp, colorful, astronomical images. Sometimes the images were taken through a telescope just like the one being sold. Yet, more often than not, no one can see the same objects when looking through the same telescope as well as the camera and (often) image-enhancing software depict them in the advertisements. It takes patience and experience to learn to see all that any telescope is capable of showing. Even then, it takes knowledge and the right attitude to appreciate what one sees.

My point? Don't expect miracles from the Galileoscope nor from any other telescope. The amount of joy that any telescope can provide is directly related to the attitude and drive of the individual using it. The most pleased new telescope owners are those that harbored no unrealistic expectations. In other words, since no beginner truly knows in advance what to expect, the clearest road toward pleasure with any telescope is the road on which one has no expectations.

I can honestly say that I've enjoyed the few sessions I've had so far using my own Galileoscope. Yet, it's with some reservation that I would recommend the same telescope to a beginner. This is because I know that the beginner would be, more likely than not, disappointed with his/her initial views. Few beginners start out with an attitude that allows for a pleasurable experience when using a relatively small telescope. Nevertheless, in my opinion the Galileoscope would make a good first telescope. Just remember to supply it with a reasonably sturdy tripod that's tall enough for comfortable use.

In my opinion it would be a mistake to provide a beginner with a far more expensive first telescope. Telescopes need tender, loving care if one wants them to last and continue to perform as well many years later as they did on their first night out. The higher a telescope's quality is, the easier it is to abuse, improperly use, and damage by ignorance and negligence. It's better to learn how to care for a telescope while using a less (rather than more) expensive instrument. This is another factor that makes the Galileoscope a good first choice.

I enjoy pushing myself as well as whatever telescope I'm using to both of our limits. This is a large part of the reason why a person like myself, who has access to larger and better telescopes, can still enjoy observing with a small Galileoscope. I'm fortunate to live in a region where I have easy access to a truly dark night sky. Though that didn't happen entirely by coincidence! A dark sky greatly enlarges the list of what one can see with any telescope. City dwellers will have to be content to observe only the brighter objects visually -- objects like the moon, Venus, Jupiter, and Saturn. Of these, the moon is likely to be of greater interest. Each night the shadows on the moon are different. Each night there's something different to see.

I started out in this hobby using a telescope somewhat similar to the Galileoscope. The hobby became far more interesting after I started recorded my observations using words and sketches. Some have started out differently while still achieving a life-long interest. Unfortunately, many others have dropped out of the hobby after spending a brief time attempting to use a telescope. To succeed one needs a usable telescope along with a die-hard attitude. Of the two, attitude is of greater importance.

So, is the Galilescope a serious telescope or a mere child's toy? The answer depends on the end user and their attitude.

Galileoscope Assembly Instructions

2009-07-26T19:43:00.004Z

For those who have or will be getting a Galileoscope, the assembly instructions that come with the telescope are not quite complete. I suggest the following modifications or additions to those instructions. It is assumed that the reader has the original assembly instructions in hand when trying to make sense of what I've written below.

Step 5 -- Modify to read: Secure the two ends of the focuser assembly with the two smaller rubber 0-rings that fit into the grooves at the ends of the tube.

Step 8 -- Add the following to the supplied instructions for this step: Slide the two larger o-rings over the telescope body, positioning them over the two grooved rings.

Pay due attention to the photos as well as the Exploded View diagrams when assembling your Galileoscope.

When assembling the Galilean eyepiece/barlow (this is the two-lens eyepiece) take care to place the convex side of one lens against the concave side of the other. When placing this lens pair into the eyepiece halves be careful to place it so the concave side faces the wider part of the eyepiece body.

Note in the exploded view the plastic covering that fits over the eye end of the Galilean eyepiece. That covering is removed when the Galilean eyepiece assembly is placed into the barlow tube for use as a 2x barlow.

Hints and Suggestions for Using the Galileoscope:

The telescope works reasonably well with a photo tripod that can be extended high enough for the observer to comfortably look upward through the eyepiece without having to squat or crawl under the telescope. In other words, a tall tripod is better than a tripod that is too short.

If you have no tripod, rest the telescope on a wall, fence, tree branch, etc. in order to steady the view. You might even be able to use one of the included cradles in a creative manner. Anything that offers steady support is better than nothing.

The Galileoscope is easier to use with the 25x eyepiece. Always start your observing with that eyepiece. For closer (50x) views of bright objects use the 25x eyepiece along with the 2x barlow. You'll probably want to switch back to 25x before seeking a new target for observation. If you find the telescope too difficult to manage at 50x then use the telescope only at 25x. None of Galileo's actual telescopes could magnify as much as 50x.

If you own other telescopes and have 1.25-inch O.D eyepieces, you can use those eyepieces with the Galileoscope. Keep in mind that the magnification is equal to the focal length of the objective (500mm) divided by the focal length of the eyepiece.

Expect nothing when using an astronomical telescope! Your views will not look like the photos that are so easy to find all over the Internet. Similarly, when used at night for astronomy expect to see no color. You should be happy with whatever you can see. The Galileoscope is a far better telescope than anything Galileo actually used, but there are plenty of other telescopes around that are better. Nevertheless, for its price, the Galileoscope is tough to beat!

The Galilean eyepiece is perhaps best reserved for demostration purposes -- in order to get a better feel for what Galileo had to work with. I suspect you'll find yourself using the telescope primarily with the 25x Keplerian eyepiece.

Galileoscope - First Light

2009-07-25T18:56:00.004Z

The above photo shows the $15.00 (plus postage) Galileoscope atop an optional (but recommended) camera tripod. My order was received yesterday. First light was last night - 25 July 2009 UT.

The telescope arrived unassembled with incomplete instructions. More complete instructions were available online. I never did find what I would call 'complete' instructions, but the remaining details I was able to figure out for myself.

The design of the Galileoscope was well thought out. All parts fit together very nicely. The objective is a high quality, 50mm glass achromat. Once fitted inside the optical tube assembly (OTA) the effective aperture becomes 47mm. The plastic eyepiece lenses do a decent job magnifying the image. The telescope can be used at 25x with the included eyepiece, 50x when the included barlow is added, or 18x if one desires to use the telescope as a true Galilean telescope (using the barlow as an eyepiece) - resulting in a narrow field of view (FOV) and erect image. In the 25x and 50x arrangements the image is upside down - typical of many astronomical telescopes, but the FOV is larger, making the telescope more comfortable to use.

Last night I observed and sketched seven astronomical targets including four galaxies (M101, M31, M32, and M110), a globular star cluster (M13), a double star (Mizar - aka Zeta Ursae Majoris), and a planet (Jupiter). A few other objects were observed but not sketched - including M33, a galaxy that some in light polluted areas cannot see even when using much larger $1,000 telescopes! I considered sketching M33, but I was getting tired and decided to go instead for the more beautiful trio of galaxies in the M31 family.

Even at 25x the FOV is rather narrow in the Galileoscope. I had to off-center M31 in order to include M32 and M110 in the same FOV.

Most of the night's observations were made at 25x. Jupiter was sketched at 25x and again at 50x. The double star was sketched only at 50x.

Jupiter's North Equatorial Belt (NEB), South Equatorial Belt (SEB), and Equatorial Zone (EZ) were all visible upon close examination at 25x. At 50x I was able to make out a zone south of the SEB and another north of the NEB. Since none of the Galilean Satellites were in eclipse or transit, all four were easily visible at 25x.

Some structured glare was apparent around Jupiter at 25x, perhaps from the uncoated, plastic eyepiece lenses. That was the only optical defect that really stood out at 25x. It went unnoticed for all other objects observed. Similarly, at 50x, the only optical problem encountered was a smooth, even glare throughout the field of view when observing Jupiter. No glare was noticed when observing any of the less brilliant targets observed. In my opinion the glare is easy to tolerate and ignore considering the price of the telescope.

I enjoyed observing and sketching the deepsky objects! Many, if not most amateur astronomers believe that 'aperture is everything' in a telescope - particularly when one wants to observe deepsky objects. In my opinion and experience a dark sky and observer experience are often of greater significance. I *really* enjoyed observing these objects with the Galileoscope!

Far Ranging Thoughts

2009-07-23T20:45:00.003Z

Last night was my best night with Jupiter this season. My third and fourth sketches of the planet for this year were completed. Excalibur was used at 218x.

For the first sketch (started at 6:45 UT) I employed a Moon-SkyGlow filter which had perhaps a subtle effect. I feel that my 'Jupiter Observing Eye' has returned now. I was able to sit down and make my most carefully rendered Jupiter sketches of this season. Callisto's shadow showed up as a small, round, pitch black spot below the trailing edge of the Great Red Spot. It looked really nice in such close proximity to Jupiter's most famous feature.

The GRS was very pale. It's leading edge was darker than it's following edge. Nevertheless, even the leading edge was very pale. Some structure within the planet's two primary belts (as well as a little zonal detail) was also recorded.

The second Jupiter sketch of the night was started at 8:50 UT. The GRS had moved to the preceding limb of the planet and was no longer visible, but the disrupted end of the South Equatorial Belt following the GRS remained visible. Callisto's shadow remained on the planet, but it now lagged a little behind the GRS.

In the second sketch the impact scar was visible near the planet's south limb. It hadn't quite reached the planet's central meridian at the time of the sketch. The scar seemed to be a little smaller than Callisto's shadow and clearly elongated in the east-west direction. It was considerably less dark than Callisto's inky, black shadow. The scar was about as dark as the matter making up Jupiter's major belts. In other words, it was far less obvious to the eye than was Callisto's shadow.

I'm hesitant to upload these latest sketches, preferring to keep them for my selfish self. Both would provide good material for future paintings -- if I ever get around to it . . .

I've recently become quite discouraged with an astronomy forum that I've been frequenting lately. Forum content has had little to offer me despite my own attempts to increase its faltering signal to noise ratio. Of course, my own lack of a full night's sleep might be adding to the feeling. Time will tell . . .

Anyway, I've been rethinking my Internet presence in general. Eventually re-working my website is a possibility. Also being considered is a limitation on my blogging -- perhaps making one entry at the beginning of each month describing one night's observing session (with sketches if applicable) from the just ending month.

I find it discouraging that there appears to be so little (relatively speaking) Internet discussion and sharing of observations relating to the recent impact on Jupiter. This is only the second time in recorded history that a Jovian impact event has been positively identified and observable with backyard telescopes.

Then there's imaging. It seems that more and more amateurs are becoming interested in setting their eyes aside and letting their cameras do the looking. With visual observing and sketching I feel that I'm in a minority special interest group within a minority hobby. I get the impression that few care to see sketches when digital cameras can show more detail and more color with less work under worse conditions. Such are a few of my thoughts in the early twenty-first century.

Impact on Jupiter!

2009-07-21T10:42:00.008Z

Date: 21 July 2009
Time: 8:52 - 9:02 U.T.
Telescope: 13cm refractor
Magnification: 218x
Seeing: Fair
NELM: 6.5
Temperature: +46 F (+8 C)

The above sketch is mirror-reversed due to the use of a star diagonal. North is up. Preceeding is to the left. The dark spot to the lower left (southwest) is a new impact scar on Jupiter. The small, dark, impact scar was spotted as soon as I looked into the eyepiece and focused the telescope at 218x.

Anthony Wesley, an amateur astronomer in Australia, was the first person to discover this impact scar on the 19th of July. Thanks to the Internet, I heard about the dark spot shortly thereafter.

Considerable fine detail was visible within the two major belts, but I would have had to up the magnification a bit (and taken more time) in order to sketch it. Meanwhile, Jupiter's rapid rotation would have taken the impact scar closer to the planet's preceeding limb and shortly thereafter onto the far side of the planet.

Sunspots: 9 July 2009

2009-07-09T19:25:00.008Z

Today's sunspot observation was made with the help of Buttercup, a 60mm achromat refractor. The above photo of Buttercup was taken shortly after I had completed today's sunspot sketch. The short cardboard tube visible on the front of the telescope is a home-made solar filter utilizing safe, Baader Solar Filter material. Permanent eye damage or blindness is likely to occur if proper safety procedures are not followed when observing the sun. The telescope's finder has black covers over both ends as a further safety measure.

Today's sketch, shown above, has north up and preceeding to the left. The image is mirror-reversed due to the use of a star diagonal. A magnification of 70x was utilized. The sketch shows just a small region within the telescope's field of view.

When sunspots are observed near the limb of the sun one should always look for faculae -- areas that appear brighter than the background solar surface. Faculae were noticed and sketched today, but those regions do not show up well in the scanned image.

July 7th Sunspot Group

2009-07-07T16:47:00.004Z

The above sketch shows the sunspot group observed from 15:54 until 16:04 U.T. on 7 July 2009. A 60mm f/11 achromat refractor (Buttercup) was used at 70x for the observation and sketch. Use of a star diagonal resulted in a mirror-reversed view. North is up and preceeding is to the left. It's good to finally see some sunspot activity on our nearest star!

Moon Occults Venus

2009-04-22T23:54:00.008Z

The above sketch shows Venus and Earth's moon after sunrise, but just before the moon passed in front of Earth's sister planet on Earthday morning. The sketch is a fairly close approximation of the view through 20x80 binoculars. East is toward the lower left. North is toward the upper left.

Later in the day I showed students our moon, Venus, and the sun using Buttercup (a 60mm refractor) at 28x. Some of the students managed to see the moon and Venus in the daytime with their unaided eyes! By this point in time Venus was a fair distance west of the moon.

Buttercup views Saturn: 16 March 2009

2009-03-16T23:56:00.003Z

Saturn and Titan were sketched last night while observing with Buttercup, a 60mm refractor. The planet was tiny at 28x and still rather small at 70x -- the magnification used for the above observation. North is approximately up. Preceding (west) is to the left. A subtle, slightly darker band was just visible (or suspected) north of and running parallel to the ring plane. The point of light to the left of Saturn is Saturn's largest moon, Titan.

Sun & Venus 15-16 March 2009 U.T.

2009-03-16T01:41:00.004Z

The above sketch shows Venus at 0:55 16 March 2009 U.T. as it appeared in "Buttercup", a 60mm refractor, at 70x. The observation was made around sunset under fair seeing conditions through thin clouds. The planet's apparent diameter was quite large. Even at 28x the planet seemed large! North is up. Preceding (west) is to the left. Though a complete disk appears in the sketch, only the bright, thin crescent was visible.

The sun appears in the above sketch with clouds sihlouetted against the bright solar disk. The observation was made through thin clouds at 28x with a full-aperture, objective solar filter at 23:10 on 15 March 2009 U.T. The densest clouds were even visible against the background sky. Unfortunately they don't show up in the scanned image of the sketch. No sunspots were noticed. Limb darkening and clouds were all that was noticed on (or in front of ) the sun's disk. The solar filter was home-made using Baader Solar Filter material. Never look at the sun without proper eye protection!

"Buttercup"

2009-03-04T03:26:00.006Z

Shown above is the same old, banged-up 60mm refractor that appeared earlier in this blog. The telescope has been improved here and there. After adding some weight inside the rear of the OTA the scope balances better in its fork. The altitude trunnions have been attached more solidly than before. The tube assemblies have been painted yellow with black trim. The wood tripod legs have had their dark paint removed and replaced with a somewhat lighter stain and varnish.

In the tradition of my other telescopes, this one also has acquired a name. Today marks the birth and first-light of "Buttercup".

Venus was Buttercup's first target. Shown above is the rough, at-the-telescope sketch of Venus made at 1:00 on 04 March 2009 U.T. at 70x. Unfortunately the sky had clouded over by the time I went back outside in the hope of observing the moon.

Comet Lulin (C/2007 N1) 22 Feb. 2009

2009-02-22T17:45:00.002Z

The above sketch shows the full-field view I had of Comet Lulin last night with 25x100 binoculars. Comet Lulin was easily visible to my unaided eyes from my dark-sky (Naked Eye Limiting Magnitude 6.5), rural location. North is up and east is to the left in the sketch. The field of view is approximately 2.3 degrees. From a dark sky any pair of binoculars will provide a pleasant view of Comet Lulin.

I've been observing this comet for a while now, but this is obviously my first blog entry on our latest celestial visitor. There's just so much to do these days . . .

Venus & Pythagoras

2009-02-08T01:00:00.005Z

The above photo shows our visiting wild turkeys on the run. I like this photo for showing some of the resemblance between wild turkeys and their T-Rex and velociraptor relatives. Really though, I felt like showing something but didn't feel like putting in the work to polish up the evening's astronomical sketches.

Venus was easily found with the unaided eye shortly before sunset. I took out the 60mm refractor and made a more careful (than last time) sketch. This time I recorded some background colors to give a better idea of the visual impression of the planet as seen in the small, low-cost telescope. I might upload a sketch later . . .

Pythagoras is a large, 130km wide lunar crater. It was prominent (and greatly foreshortened) along the terminator of this evening's gibbous moon. Pythagoras's central peak was very obvious, standing out as a bright notch in the non-illuminated portion of the crater. The nearby 144km wide crater Babbage, with Babbage A within its border, aided in positively identifying Pythagoras.

I have only one 0.965 O.D. eyepiece -- the size that fits the 60mm refractor's diagonal. Therefore I'm currently restricted to using only one magnification (28x) with this telescope.

Venus - 02 February 2009

2009-02-02T02:57:00.005Z

The above sketch of Venus depicts the general appearance of the planet on 02 February 2009 at 0:40 UT at about 30x with a 60mm f/11 achromat. West is to the lower left. North is to the upper left. Of course, at 30x the planet didn't look as large as it appears above, but the fat crescent was none the less sharply defined and easy to see.

Interestingly, a 60mm f/11 achromat is virtually free of false color at 30x. Venus as well as our own crescent moon were sharply defined with little false color (chromatic aberration). Galileo would have loved to use a telescope like this!

It was unnecessary to provide any specific cool-down time for the small refractor. The outside temperature was about 40 degrees (F) cooler than the inside temperature. Yet the image was sharp and crisp when I looked into the eyepiece. Smaller telescopes have some disadvantages, but they also have their advantages!

Meade Model 226 60mm Refractor

2009-02-01T23:09:00.015Z

Shown above is a newly acquired, old, Meade model 226, 60mm alt-az refractor. I had to replace seven missing screws of one kind or another. When acquired, the scope was in its mount backwards. That situation was remedied prior to taking these photos. The prism diagonal had to be removed for a proper cleaning. Somewhat surprisingly, all optical surfaces were totally without visible scratches!

This fixer-upper scope will be used partially for educational purposes (how to make the most of the least, etc.) and partially for me to take notes and make sketches regarding what can be seen with such a telescope.

Note the stopped-down aperture of the finder: The purpose of a stopped-down aperture is to mask aberrations (distortions) that would otherwise be visible when looking through a telescope that has a poorly designed objective. Such finders can be useful under daytime and twilight conditions, but used under a dark sky for anything other than the brightest of targets they can become liabilities. I found it easier to see poorly illuminated terrestrial objects with the naked eye than with this finder! If your child's telescope has a finder like this I would suggest replacing it with something more useful such as one of the many 1x red-dot finders (or a 5x24 finder that is not stopped down) that are available now.

I'll keep the original finder on this scope for educational purposes and for those occasions when it remains of some use. An experienced observer would have little difficulty in sighting along the primary scope's tube to successfully point it as long as the telescope's magnification isn't too high, but a child might easily become frustrated without a more useful finder.

The telescope's objective is clean and scratch free, though when the scope was first acquired the objective was filthy!

At some future date, when weather and time permit, I hope to re-paint the telescope, re-finish the wood tripod legs and make some final tweaks to enhance the scope's usefullness.

IYA2009, Venus, new Barlow, & Turkeys

2009-01-25T21:24:00.004Z

The above photo was taken yesterday through a window (two panes of glass and a screen). The three turkeys are shown at the base of a tree where a couple of bird feeders are hung. The turkeys seem to be attracted to the seeds that are scattered about on the ground. The same three turkeys have been dropping by for the past week. They tend to not trust humans and quickly run away if anyone ventures outside.

Orion's new 5x HighLight Barlow: As with most products, this one has some strengths as well as some weaknesses. I've made extensive notes concerning the barlow's performance. I checked out vignetting and kidney-beaning in the daytime with all of my 1.25" eyepieces. Color correction was checked out (with good results) on Venus using a high quality telescope. The magnification factor was checked with a Celestron Micro-Guide eyepiece . . .

This barlow is not threaded for filters. I found it helpful to add a ring of tape around the barrow in order for it to seat a bit better when inserted into an eyepiece holder. The set-screw that tightens and loosens the clamp that secures the eyepiece in the barlow has unusually coarse threads. One needs to be careful not to loosen it too far - else the set-screw may fall to the ground. There's a limit to how far an eyepiece may be inserted into the barlow before encountering a smaller diameter obstruction (I don't have my notes handy at the moment to provide the actual limit). Most, but not all of my eyepieces could be inserted all the way into the barlow.

If I get ambitious I'll do a reasonably detailed review at some future date. I would like to do a little more testing on the moon and/or planets under good seeing conditions. So far I'm satisfied with the barlow's optical performance. I don't find the various drawbacks to be overly severe. This barlow was purchased primarily for use with my Micro-Guide eyepiece to provide sufficient magnification to better make measurements of double stars, etc. It looks like this barlow may prove beneficial for other purposes, such as lunar and planetary observing, as well.

Venus is looking good! This planet is very well positioned in the evening sky for northern hemisphere observers. The planet's phase is slightly less than quarter. I've made a couple of Venus observations this year. A #58 green filter was used for sketches, but the filter was removed to check out the 5x barlow's color correction. I was easily able to spot the planet with the unaided eye shortly before sunset one evening.

2009 is the International Year of Astronomy! Four hundred years ago, in 1609, Galileo began his ground-breaking adventures in telescopic astronomy.

Measuring the Sky

2008-10-17T13:21:00.004Z

Above is a sketch showing approximately what's seen when one looks through a Celestron Micro Guide eyepiece. The linear scale has a real length of 6 millimeters. Adjacent scale divisions are 1/10 of a millimeter apart. I'll be using the Micro Guide eyepiece to make a variety of measurements while using Excalibur - my 13cm refractor.

The separation distance between scale divisions will of course vary depending upon the magnification that the eyepiece provides with a given telescope. My measurements indicate that the divisions are about 24.80 seconds of arc apart when the eyepiece is used with Excalibur without a barlow. With my three barlows the divisions become 11.06, 10.36, and 7.84 arc-seconds apart.

The linear scale will be used to measure linear distances such as the separation of double stars. The outermost circular scales will be used to measure position angles.

I was stricken be a sore throat on the 5th of October. Some congestion and an occassional cough remains. Hopefully it's not progressed to bronchitus or pneumonia. Currently I'm not sure if this situation is getting better or worse, but at the moment I'm feeling healthier than I was earlier. I might be feeling up to at least a brief observing session tonight. I stepped outside this morning in time to catch sight of Saturn in the east-southeast with the unaided eye.

RA 20h 40m to 21h 00m, Dec -09 to -15

2008-10-02T12:49:00.003Z

Last night I observed and sketched two double stars as well as M72, M73, and an un-named (as far as I know) small asterism similar to M73.

The session actually began with a sighting of the International Space Station gliding across the sky. The ISS appeared to be somewhat brighter than Jupiter -- a rather brilliant, white, moving light in the sky. Of course, as the ISS entered the earth's shadow it rapidly dimmed.

The seeing was 'good' -- a '6' on the modified Pickering Scale. I used 477x for the seeing check.

My NELM was 6.5.

Observations and sketches were all made at 135x, though other magnifications were used at times.

RA 20h 20m to 20h 40m, Dec -09 to -15

2008-10-01T12:21:00.004Z

The mushroom cloud shown above was visible in the west this afternoon, but fortunately the smoke drifted south of me and the fire may have been successfully supressed by nightfall. The photo is an enlarged (and somewhat enhanced) portion of the original telephoto. The fire was not as close it may appear above. My sky appeared to be 'crystal clear' by the time I had begun my observing session.

In this region of sky (see title) I observed, split, and sketched seven double stars in the course of a little over an hour with the 13cm refractor. One was particularly nice, showing some color at low power. Another was a particularly close 'split'.

Seeing was much better on this evening (Tuesday evening, September 30th locally or October 1st UT) than it was on the previous evening. I rated it as being "Excellent" -- an "8" on the modified (for a 5-inch scope) Pickering Scale.

RA 20h 00m to 20h 20m, Dec -09 to -15

2008-09-30T12:57:00.003Z

Four double stars were observed, split, and sketched in this region of sky last night. Seeing was 'good' (a '6' on the modified Pickering Scale). Temperature was +52 degrees F (+11 C). The 13cm refractor was used on an equatorial mount with clock-drive engaged.

My long-term goal: to cover the entire sky visible from my location - recording all visible objects of interest using my 13cm refractor. This isn't a new goal. Instead it's a revision of an earlier goal with a bit of modification. Time will tell if this 'new' program can stay alive.

Polar Doubles Revisited

2008-09-29T12:47:00.004Z

Last night I re-observed the double stars listed in my previous blog entry. The seeing was a bit better this time around. Sketches, with north carefully noted, were made of all five double stars. A magnification of 135x was used for all of the double star sketches.

Prior to the double star observations I trained the scope on Jupiter -- as an object to focus on prior to adjusting the scope in its cradle. Balance is more sensitive for my home-made alt-az mount than it is for my equatorial.

As the bright twilight gradually faded, more stars popped out in the vicinity of Jupiter. A sketch was made at 43x of Jupiter, its moons, and some of the background stars. The seeing varied from poor to extremely poor at this point in time, but it had improved noticeably by the time I trained the 13cm refractor on the double stars.

My work schedule prevents me from making a more detailed post or refining and uploading sketches at this point in time.

Starting at the North Pole

2008-09-27T18:32:00.004Z

Date: 27 September 2008
Time: 3:15 - 5:30 UT
Telescope: 13cm refractor
Mount: home-made alt-az
Diagonal: 1.25-inch 90-degree erect-image prism
Magnifications: 43x, 80x, 111x, 302x
NELM: 6.5
Seeing: very poor ('3' on Pickering Scale) - at session end
Temperature: +50 F (+10 C) - at session end

Using the Millennium Atlas as my guide I sought out objects within about 3-degrees of the north celestial pole.

The star diagonal used is not of the highest quality, but for an erect-image diagonal it is of reasonable quality. This diagonal was used in order to more easily match the eyepiece view with the detailed atlas charts.

My old alt-az mount was used under the assumption that it would make it easier to navigate around the celestial pole -- easier than using an equatorial mount. At a later date I'll determine whether or not that assumption reflects accurately on reality.

The seeing and temperature were not recorded until the end of the session. A high magnification (302x in this instance) was necessary in order to obtain an accurate value for the astronomical seeing. For all other observations the maximum magnification used was 111x.

Five double stars were 'split' on this evening. Their rough coordinates are given below:

RA 02h 35m, Dec +89.3 degrees (Polaris, Alpha Ursae Majoris) very bright primary with much fainter secondary

RA 08h 20m, Dec +87.25 easily split at all magnifications, not particularly bright

RA 12h 00m, Dec +87.0 a nice double, best at about 80x

RA 12h 30m, Dec +88.7 a close, unequal double, cleanly split at 80x

RA 18h 40m, Dec +88.3 an unequal, easily split double (140 lightyears distant)

Other objects and double stars were looked for, but were either not positively seen or not positively split.

Saturday Evening: Venus in the West

2008-09-14T03:07:00.004Z

After a cloudy day with intermittent, light precipitation I was greeted by a mostly clear sky after sunset. The tiny point of light near the bottom center of the image is Venus. Clicking on the image will reveal a somewhat enlarged view.

Lunar Limb - Daylight Observation

2008-08-24T23:23:00.008Z

Date: 24 August 2008

Time: 17:18 - 17:33 U.T.

Telescope: 80mm f/5 achromat

Magnification: 70x

Filter: Polarizing

Seeing: Fair - Good

NELM: Daylight

Temperature: +85F (+29C)

Wind: Calm

Transparency: Very Good (cloud-free sky

The above sketch shows two lunar mountains that were silhouetted against the darker sky background. North is up. Lunar East (preceding) is to the left in this mirror-reversed view. The sketched region is at 90 degrees west longitude and approximately 12 or 14 degrees south latitude. The moon was a fat, waning crescent at the time of the observation.

Not shown in the sketch is Lacus Aestatis which was seen as a dark patch to the left of the lower mountain peak beyond the sketched region. A very rough, larger scale sketch was made to facilitate finding this region on a lunar map. That sketch showed Lacus Aestatis, Cruger, Grimaldi, and Riccioli all as dark patches.

The sun was still spotless today. I used the 80mm refractor at 24x. A glass, white-light solar filter covered the front of the telescope. The filter gave the sun a soft, golden, peachy color. There was something aesthetically pleasing about observing a spotless sun through a telescope with one's own eyes.

Venus and Mercury in Evening Sky

2008-08-20T02:31:00.005Z

For the past three evenings I've managed to see these two planets low in the western sky shortly after sunset. Brilliant Venus has been the easier planet to spot. Dimmer Mercury has been between one and two degrees to the lower right of Venus.

Binoculars seem to be better suited for catching these two planets than a telescope. The sky has been too bright at prime observing time for Mercury to be seen with the unaided eye.

This evening I set up a small, 80mm f/5 refractor on the porch. Venus was easily visible, but trees blocked Mercury from view. From nearly the same location I managed to see both planets with 20x80 binoculars. This was primarily because my eye level with the binoculars was a little higher than the telescope -- just enough to bring Mercury above the trees.

On the previous two evenings I viewed the two planets with 8x42 binoculars as well as with the 20x80s. Mercury was easier to see with the 20x80s. Venus showed up easily with either pair of binoculars. Once I knew where to look, Venus could also be seen with the unaided eye.

On all three evenings I had to look thru thin clouds when observing Venus and Mercury. The clouds appeared to have formed near the time of sunset low in my western sky. They showed up as horizontal bands of varying thickness, but not thick enough to block the planets from view with binoculars.

Meanwhile, Jupiter shines brightly in the south-southeast. Jupiter and its brightest moons are not difficult to see with either tripod-mounted or steadily held binoculars.

Our Spotless Star

2008-08-12T17:58:00.004Z

The above photo of the sun was taken today, 12 August 2008. A DSLR camera was used at the prime focus of a 102mm (700mm focal length) Schmidt-Cassegrain telescope. A full-aperture, white-light solar filter covered the front of the telescope.

I knew the sun was without spots today - as it has been for quite some time now. Nevertheless, even a spotless sun can be of interest. Notice that the limb (edge) of the sun is darker than the center of the sun. This is called "limb darkening" and is due to much of the solar radiation originating deep within the interior (rather than the 'surface') of the sun.

The sun goes through a roughly 11-year sunspot cycle. Approximately 11 years pass between sunspot maximums. Sunspot minimums occur roughly midway between the maximums.

Shooting the Moon

2008-08-12T04:47:00.004Z

Shown above is a 'snapshot' of this evening's gibbous moon. It was taken under poor seeing conditions with a DSLR camera attached to a 102mm Schmidt-Cassegrain telescope (about 700mm focal length). This was one of two experimental images I took of the moon. The telescope's tripod was set up on my south porch - not the most stable of platforms, but sufficient for experimental purposes.

The Perseid Meteor Shower should be near its peak after the moon sets later tonight. If you read this early enough (Monday night - very early Sunday morning), have adequate sky conditions, and can affort to lose the sleep (a lot of 'ifs') you might want to spend some time lying back, staring at the sky, and counting meteors.

What is a planet?

2008-08-12T01:01:00.006Z

What is a planet? In my opinion any astronomical body that's essentially massive enough to maintain a spherical shape, but not massive enough to trigger a self-sustaining fusion reaction (becoming a star) should be considered a planet.

Looking over the known bodies in our solar system, it seems that a reasonable cut-off at the low end would be 10e20 (one with twenty zeros) kilograms. Some solar system bodies with a mass in the 10e19 range are reasonably spherical, others are not. Since it's desirable to have an unambiguous definition (based solely on mass - which is one of the most easily determined properties of solar system bodies) it seems reasonable to fix 10e20 kilograms as the lower limit for planetary status.

The upper limit would be more flexible (as far as mass goes). The primary criteria here is that the body in question is not a star - that is, it does not generate a self-sustaining fusion reaction. For objects otherwise similar to those in our solar system, this limit would likely lie within the 10e28 kilogram mass range.

Planet Classes can now be designated as:

Class 0 -- with masses in the 10e20 kilogram range

Class 1 -- with masses in the 10e21 kilogram range

Class 2

Class 3

Class 4

Class 5

Class 6

Class 7 -- with masses in the 10e27 kilogram range

Class 8 -- with masses in the 10e28 kilogram range

Jupiter would be a Class 7 planet. Earth would be a Class 4 planet. Pluto would be a Class 2 planet. Tethys (one of Saturn's moons) would be a Class 0 planet.

Bodies with masses less than 10e20 kilograms could be referred to as "subplanetary" and designated as lying within Subplanetary Class -1, Subplanetary Class -2, etc. for masses in the 10e19 and 10e18 kilogram ranges respectively.

Note that the location of an object is not relevant in this system. The object is classified the same regardless of whether it orbits a star or a planet. A Class 5 planet, for example, could even be adrift in interstellar space.

Jupiter's Family via 25x100 Binoculars

2008-08-01T21:49:00.003Z

Shown above are two sketches of Jupiter and its brightest moons as observed on 1 August 2008 U.T. The uppermost sketch was made at 3:15 U.T. The lower sketch was made at 7:25 U.T. The lower star at the far left is an actual star, not one of Jupiter's moons. Europa was in transit across Jupiter's disk (and not visible in the large binoculars) at the time of the first sketch, but by the time I had started working on the second sketch it had reappeared off Jupiter's preceding (western) limb.

Jupiter's North and South Equatorial Belts (the dark bands running parallel to Jupiter's equator) were visible in the tripod-mount 25x100 binoculars. Seeing conditions were rather poor on this night. Jupiter's moons and the various field stars appeared to twinkle due to earth's unsteady atmosphere. A haze (most likely from forest fire smoke) seemed to fill much of the sky as well.

My First Star Field Photo

2008-08-01T21:28:00.004Z

This is my first (and so far only) photograph of the night sky taken with my new camera. I attached the camera to a homemade equatorial wedge (built for a 102mm SCT) and set the assembly on my north porch. The "Little Dipper" asterism can be seen offset toward right center. Some nearby tree tops are silhouetted against the brighter night sky at the bottom of the photo.

Digital photography is certainly far more user friendly than film photography! One gets to see the results right away, and PCs make it easy to tweak the images as necessary. The above photo is a 30 second exposure at ISO 800 with an 18mm lens at f/3.5. It was taken at 11:59 pm local time on July 31, 2008.

Comet C/2007 W1 (Boattini)

2008-07-13T22:38:00.006Z

Date: 13 July 2008 U.T.
Time: 9:40 - 9:50 U.T.
Telescope: 13cm refractor
Magnification: 66x
NELM: dark twilight, growing brighter
Temperature: +41 F (+6 C)

The above sketch shows an approximately 0.54 degree wide portion of the telescopic field centered on Comet Boattini. North is up. West is to the left in this mirror-reversed view.

Comet Boattini is currently visible with binoculars in the early morning sky, low in the east, prior to the onset of bright twilight. The time of this observation in local time was 3:40am - 3:50am. Earlier the comet would be seen in a darker sky, but it would also have been closer to (or even below) the horizon. Later, morning twilight would have had a more drastic, negative effect on the comet's visibility. This comet will be climbing higher in the morning sky with each passing day, but moonlight will soon add a negative element to this comet's visibility.

Comet Boattini is heading out away from the sun now, so it can be expected to grow smaller and fainter in the upcoming weeks. Currently the comet appears like a round 'fuzzball' with an outer boundary the blends into the background sky. The comet is brighter closer to its center. I noticed no tail and no central condensation (or pseudonucleus). This comet was not visible to my unaided eyes - at least not under the twilight sky in which this observation was made.

This comet looks like a typical, relatively bright, telescopic comet. That is, it's easily visible with a telescope or even binoculars; but it has no (visible) tail and presents nothing out of the ordinary to see - at least not at this time.

Binocular & Small Telescope Session

2008-01-13T18:51:00.000Z

Date: 13 January 2008
Time: 3:05: 3:25 U.T.
Binoculars: 8x42 & 20x80
Telescope: 80mm f/5 Achromat
NELM: 6.0 to 6.5

Comet Holmes was visible to the unaided eye, but it was significantly better with the binoculars. A crescent moon was above the horizon to the southwest, but appeared to have little if any adverse effect on the evening's viewing. Clouds were approaching from the west.

Mars looked like a tiny, yellow-orange disk in the ST-80 at 105x without filters. Markings on the planet were difficult to see with the small telescope, but they became easier when the planet's brightness was reduced and contrast was increased via the use of a #23A Light Red filter. The #23A filter transformed the color of the planet to a orange-red. Normally I wouldn't consider using such a small telescope on Mars, but I was curious concerning what could be seen with minimal optical aid. Without any filters, the ST-80 is likely to disappoint just about anyone when viewing Mars. With filters, a fair amount of patience, a bit of observer experience (and a good solid mount!) it's possible to conduct some regular study of Mars when the planet is near opposition, but I would strongly suggest that any interested observer use a larger, higher quality telescope.

Surface markings were ill-defined and difficult to pinpoint in location due to the telescope's small aperture, the relatively low (for Mars) magnification, the less than perfect (achromatic) optics, and the somewhat uncooperative, home-made mount (One of these days I should add a friction adjustment to the mount's altitude axis).

After Mars I lowered the magnification to 22x using a wide-angle eyepiece. I took quick looks at the Great Orion Nebula, the Andromeda Galaxy (and its two nearby satellite galaxies), M33, and Comet Holmes. The ST-80 and its home-made, alt-az mount seem to perform at their best when used for such low magnification purposes. All of these objects were very pleasing in the small, short telescope. Comet Holmes looked like a fairly bright, diffuse (amorphous) cloud occupying approximately one-third of the 3.34 degree field of view.

In the course of the evening's short session I never felt any need to uncap the telescope's finder. It was easy enough to point the telescope at Mars, etc. with the 22x eyepiece in place prior to switching to higher power.

I brought the telescope and mount inside, leaving the tripod out in case I decided to try out a 102mm (4-inch) SCT on Mars. Later, when I went back outside, I discovered a cloud covered sky and frost on the tripod. It was clearly time to bring the tripod inside and wait for another clear night.

Two Bright Comets

2008-01-02T05:01:00.000Z

Date: 2 January 2008
Time: 4:30 - 4:50 U.T.
Instrumentation: Binoculars and Unaided Eye
NELM: 6.5 or better
Temperature: +3 F (-16 C)

Comet 17P/Holmes remains an easily visible naked-eye comet. I was able to immediately spot and recognize this comet with the unaided eye upon stepping outside. The view was improved with 8x42 binoculars, and improved even more with 20x80 binoculars. Comet Holmes has increased in size and become a bit more diffused in appearance since my last blog entry.

Comet 8P/Tuttle was initially spotted near the Aires - Pisces border with the 8x42 binoculars. It was better seen (as a circular haze with a brighter center) with the 20x80 binoculars. At times I suspected Comet Tuttle as being visible to the unaided eye, but I was never 100% convinced.

These observations were made from my south porch after a period of indoor dark adaptation. The floor of the Colosseum (my open-air observatory) has been coated with a layer of ice for the past couple of weeks. Thus it would be ill advised to set up a telescope at that location.

Future Plans: At present I'm inclined to make fewer blog entrees and post even fewer sketches in 2008; but one never knows for certain what the future may hold.

Comet 17P/Holmes (12 Dec. 2007 UT)

2007-12-12T03:55:00.000Z

Date: 12 December 2007

Time: 2:05 U.T.

Instrumentation: 20x80 Binoculars

Seeing: Good

NELM: 6.5 or better

Temperature: +21 F (-6 C)

The above sketch shows the full, three degree field of the 20x80 binoculars. North is up. West is to the right. Not all of the field stars that were seen were recorded in the sketch.

Comet Holmes is now clearly larger in apparent size than a full moon. (The apparent diameter of a full moon is about 0.5 degrees, or one-sixth of the binocular field.) As I was observing this comet I was reminded of the general appearance of a fossilized trilobite.

Comet Holmes remains easily visible to the unaided eye. It appeared to be clearly brighter than the nearby Perseus Double Star Cluster.

Comet Holmes (10 Dec. 2007)

2007-12-10T02:54:00.000Z

Date: 10 December 2007 U.T.
Time: 2:40 U.T.
Instrumentation: Unaided Eye, 8x42 & 20x80 Binoculars
Seeing: Good
NELM: 6.5
Temperature: +15 F (-9 C)

Comet Holmes continues to be easily visible to the unaided eye -- at least from a dark sky. To the unaided eye the comet looks like a round, nebulous patch of light that's somewhat comparable to a full moon in angular size.

With 20x80 binoculars the comet had the appearance of a huge, oval (somewhat egg-shaped) patch of light occupying roughly one quarter of the binocular's three-degree field of view. The comet's sunward side was somewhat better defined than its fuzzier, anti-sunward side. Gone is the distinction between an inner and outer coma. The previously visible outer coma has probably enlarged and faded too much for my eyes to notice. No tail was noticed.

Within the comet's coma was a distinctly brighter bar of light. The bar was brightest and widest on its sunward end. Several stars were visible through the comet's coma. The comet's pseudo-nucleus was not visible. Comet Holmes now has the appearance of a giant, celestial Easter egg.

The view with 8x42 binoculars was essentially a smaller version of the 20x80 binocular view. At this point in time binoculars probably provide better views of this comet than most telescopes can provide.

I've made a few other observations of Comet Holmes between this blog entry and my previous blog entry; but other interests, activities, and necessities have taken precedence over blogging. Such is life . . .

Comet 17P/Holmes (03 Nov. 2007 UT)

2007-11-03T05:49:00.000Z

Date: 03 November 2007
Time: 2:18 - 2:40 UT
Instrument: 25x100 Binoculars
Mount: Altaz/Tripod
Seeing: Good
Transparency: Good
NELM: 6.5 or better
Temperature: +27 F (-3 C)

Shown above is the full 2.33 degree field of view of the large, 25x100 binoculars with Comet Holmes near the center. West is up, and north is to the left. The sun is toward the north-northeast. Many of the fainter stars that were visible were not included in the sketch.

The comet's inner coma was sharpest and brightest on its sun-facing side. The outer coma was noticeably more diffuse, fainter, and less sharply defined than it has appeared previously.

The brighter portions of the comet (within the inner coma) were a subtle greenish-blue color. The color was initially noted with the 25x100 binoculars, but was even more apparent with de-focused 8x42 binoculars.

This comet has pretty much maintained its brightness over the past several nights. It remains easily visible to the unaided eye as a moderately bright 'fuzzy star'.

When scanning the sky with 8x42 binoculars in the general vicinity of the comet this evening I spotted the diffuse glow of the nearby open star cluster NGC 1528.

This observation was made in the evening, local time. The comet was also briefly observed and sketched on the previous morning using 20x80 binoculars.

Comet 17P/Holmes (30 Oct. 2007 UT)

2007-10-30T05:18:00.000Z

Date: 30 October 2007
Time: 2:45 UT
Instrument: 20x80 Binoculars
NELM: 6.2
Transparency: smoky sky

The above sketch gives some idea of the appearance of Comet 17P/Holmes with 20x80 binoculars under a darker (moonless) sky. The comet's outer coma, which was not seen previously under bright moonlight is now easily visible. North is approximately to the upper left; and west is approximately to the upper right in this erect-image view. The binoculars were used hand-held. A wall provided an anchor to steady the view.

A subtle 'rift' was visible along the northeastern edge of the comet's bright inner coma. The southwestern extremity of the outer coma appeared to be a bit darker and more diffuse than elsewhere. The presence of the comet's bright pseudo-nucleus was hinted at as a brighter spot near the center of this fascinating comet. For reference purposes, the sun is to the northeast (to the left at a slight downward angle from the comet).

At the time of the observation the orange (from a smoke filled sky) moon was just rising. Comet Holmes is bright and distinctly non-stellar (though still rather small) to the unaided-eye. The comet's coma has been steadily growing larger since the outburst that occurred about one week ago. One of many sources of information and images on this comet can be found at http://www.spaceweather.com/

Comet 17P/Holmes (28 Oct. 2007 UT)

2007-10-28T05:27:00.000Z

Date: 28 October 2007
Time: 2:08 - 2:17 UT
Telescope: 130mm Refractor
Magnification: 111x
Seeing: Good
NELM: 5.0 (Bright Moon)
Temperature: +39 F (+4 C)

The above sketch shows Comet 17P/Holmes. South is up, and west is to the right in this mirror-reversed view. The bright, stellar pseudo-nucleus was easily visible on this night using the 5.1 inch refractor. As in previous sketches, some bright cometary material is visible on the southwest side (the side opposite the Sun) of the pseudo-nucleus. Also noted was a brighter ring near the outer edge of the comet's outer coma. This ring appeared
to be somewhat less bright to the southwest, perhaps due to the sunlight having to pass through the rest of the comet's coma in order to provide illumination.

No color was noticed at 111x; but at significantly lower magnifications the comet appeared to have a subtle, yellowish tint. The view is aesthetically more pleasing at lower magnifications; but higher magnifications (such as 111x) make it easier to see some of the details.

Comet Holmes remains very bright in the night sky and is visible to the unaided eye as a slightly fuzzy star. Even the slightest optical aid (such as a small pair of binoculars) is sufficient to reveal the non-stellar nature of this interesting comet.

Comet 17P/Holmes (27 Oct. 2007 U.T.)

2007-10-27T04:27:00.000Z

At 2:06 U.T. on 27 October to the unaided-eye Comet Holmes looked like an ever so slightly bloated, pale yellow-orange star. It was definitely brighter than Delta Persei and seemed to be slightly brighter than Gamma Persei.

At 2:22 U.T. with 8x42 binoculars the comet appeared to have a slight yellow-orange color. It appeared as a small bright spot surrounded closely by a somewhat less bright coma. The bright spot appeared off-centered even at the low, 8x magnification.

At 2:31 U.T. with hand-held 20x80 binoculars (an outside wall was used to steady the view) Comet Holmes was very beautiful indeed! An off-centered (south of center) pale yellow-green bright spot was visible within a larger, less bright yellow-blue-green coma. The outermost edge of the coma seemed to have a slightly reddish tint. The comet looked very much like a planetary nebula.

From 3:08 until 3:26 U.T. I observed and sketched the comet with a 102mm SCT at 80x. The comet appeared to be a bit "fuzzier" (less sharply defined) than it was on 26 October. The central pseudo-nucleus was at the limit of visibility. Most of the time it was invisible; but from time to time it could be seen with certainty. The larger bright spot appeared shifted southwestward of the center of the coma. The outer 'edge' of the bright spot as well as the outer edge of the coma appeared fuzzier and less distinct than they appeared on 26 October. Only shades of gray were noted in this telescopic view. The comet has been steadily increasing in size ever since its sudden, unexpected brightness outburst.

The temperature at the beginning of this session was +32 degrees F. At the end it was +30 degrees F. My NELM (Naked-Eye Limiting Magnitude) was 4.9 on this (nearly full) moonlit night.

Comet 17P/Holmes was significantly fainter than Pluto a few nights ago -- too faint to be seen visually with most amateur telescopes. Then it brightened tremendously, becoming nearly one million times brighter, bright enough to be easily visible to the unaided-eye even in the presence of a full moon!

I've seen many comets; but Comet Holmes is the only one I've seen that has looked so much like a planetary nebula and so little like a comet. The current apparition of Comet Holmes will surely find its place in the astronomical history books!

Comet 17P/Holmes

2007-10-26T12:43:00.000Z

Below are some recent sketches of Comet 17P/Holmes with brief notes below each. Notes are brief due to limited time. This blog has just been "cleared" so that I can once again make postings and I need to leave for my day-job in a few minutes . . .

Above is a sketch made from 1:58 until 2:10 UT on 26 October 2007. A 102mm SCT was used at 80x for this observation. North is up and west is to the left in this mirror-reversed view.

Note the tiny star-like pseudo-nucleus in the center of the larger glow and the broad, fan-shaped region south of center.

Above is a close-up of the visual appearance of the comet as seen with tripod-mounted 25x100 binoculars from 1:30 until 1:52 U.T. on 25 October 2007. North is up and west is to the right in this view.

Above is the full-field view of the comet on 25 October (1:30 until 1:52 U.T.) as seen with the 25x100 binoculars. The apparent size of the comet has been enlarged a little to better show the comet and its brightness relative to the stars in the field. Also shown is the observing form I now use for many of my sketches.

Jupiter 11 Sept. 2007 U.T.

2007-09-11T02:57:00.000Z

Date: 11 September 2007 U.T.

Time: 1:35 - 1:47 U.T.

Telescope: 13cm refractor

Magnification: 138x

Seeing: Very Poor - Fair

NELM: Twilight

Temperature: +68 F (+20 C)

Shown above is my rough, at-the-telescope sketch of Jupiter. North is up. Preceding is to the right. As part of an experiment a 1.25 inch, 90-degree, erect-image diagonal was used. Also in use was a new filter wheel; but no filters were used during the making of the above sketch. The filter wheel was loaded with various filters for deepsky use; but the planned observing session was cut short due to clouds and high humidity.

Jupiter's North Equatorial Belt was the darkest feature on the planet. It had a subtle, somewhat rusty color. The other belts on the planet appeared to be blue-gray in color. The following limb of the planet was somewhat darker than the preceding limb due to the sun angle (a phase effect).

At times the seeing was very bad, leaving nothing more than the NEB visible on the planet. At other times the seeing was fair, approaching good. The seeing was both, worse at times and better at times than it was for my previous Jupiter observation; but for the most part it was better.

Jupiter & Lambda Ophiuchi

2007-09-03T05:48:00.000Z

Date: 03 September 2007 U.T.
Time: 2:03 - 2:15 U.T. (Jupiter)
Telescope: 130mm refractor
Magnification: 138x (Jupiter)
Filter: Moon-SkyGlow (Jupiter)
Seeing: Poor to Fair
NELM: Twilight (Jupiter)
Temperature: +83 F (+28 C) (Jupiter)

The above rough (at the telescope) sketch of Jupiter has North up and Preceding to the left.

Due to poor seeing conditions small-scale, moving "ripples" were constantly visible around the limb of the planet. The "star" to the upper right of the planet is Io, one of Jupiter's moons. A little later in the evening Io was seen in transit across the planet's disk. The following limb of the planet was slightly darker than the preceding limb due to the sun angle (a slight phase effect). At times more detail was visible; but under the circumstances (poor seeing and a relatively quick observation and sketch) some of the details shown may not be particularly accurate.

The planet's North Equatorial Belt (the darkest belt on the planet) appeared brownish-red in color. Other features had colors that were too subtle to differentiate from shades of gray.

After completing the Jupiter observation I observed and sketched Lamda Ophiuchi A&B, a close double star. The above sketch (greatly enlarged from the telescopic view) shows this double with North up and West to the left. A #82A Light Blue filter sharpened the view a bit under the relatively poor seeing conditions. The "A" star appeared to have a yellow or yellow-orange color while the "B" component appeared bluish. A narrow gap was visible between the two stars during intervals of somewhat improved seeing conditions. A weak, broken, diffraction ring was also visible at times around the two stars. A magnification of 218x was used for this observation.

Venus - 13 July 2007

2007-07-13T03:27:00.000Z

Date: 13 July 2007 U.T.

Time: 2:50 U.T.

Telescope: 80mm f/5 achromat

Magnification: 85x

Filter: #56 Light-Green

Seeing: Fair

NELM: Bright Twilight

Temperature: +80 F (+27 C)

The above (mirror-reversed) sketch has North up and Preceding to the left. It shows the basic appearance of Venus as seen in a small telescope.

As the planet's phase changes from full to quarter (half) to crescent to new the planet's disk appears larger and larger. When Venus's phase is near full the planet is on the far side of the Sun. When the planet is a crescent it's on the near side of the Sun. These changes have a dramatic effect on the apparent size of the planet as seen in a telescope.

Currently Venus is moving closer to Earth as it orbits the Sun. As a result it's appearing increasingly larger as seen in a telescope and its phase is becoming a thinner crescent.

Venus is currently visible in the evening sky in the west immediately following sunset. It's by far the brightest object in that area of sky and readily visible to the unaided eye.

Comet LINEAR - 12 July 2007

2007-07-12T15:40:00.000Z

Date: 12 July 2007 U.T.

Time: 6:32 U.T.

Telescope: 30cm Newtonian

Magnification: 90x

Seeing: Fair

NELM: 6.5

Temperature: +58 F (+14 C)

After the previous night's look at C/2006VZ13 LINEAR with binoculars I decided to have a go at it with a telescope.

In the above sketch South is up and West is to the left. I experimented with magnifications from 60x to 120x before settling on 90x as my preferred magnification for this comet. I worked on the sketch for 20 minutes while observing the comet; but the comet's position was "frozen" (in relation to the stars) at 6:32 U.T.

For those unfamiliar with comets, the stars in the vicinity of the comet in the above sketch are different from those seen on the previous night's sketch. This is because comets are solar system objects that are moving in orbits around our central star (the Sun). They appear to slowly move against the background stars. It can take seconds, minutes, or hours before one notices the motion - depending on the comet, its distance from the Earth and Sun, and the solar system geometry of the line of sight.

This particular comet looks pretty much like a "generic" telescopic comet. There's no easily visible tail. The comet simply looks like a circular, fuzzy, disk of light with a brighter central region. This is what most telescopic (and binocular) comets look like.

Comet C/2006 VZ13 (LINEAR) & Aurora

2007-07-11T06:46:00.000Z

Date: 11 July 2007 U.T.
Time: 5:50 U.T.
Instrument: 20x80 Binoculars
Seeing: Steady (for binoculars)
NELM: 6.5
Temperature: +55 F (+13 C)

The above sketch shows the basic appearance of Comet C/2006 VZ13 LINEAR as seen with hand-held 20x80 binoculars. Only a few of the many visible field stars appear in this sketch. South is up. West is to the left. The comet is the large, round, nebulous object with a brighter middle. The galaxy, NGC 6015 was visible in the 20x80 binoculars as a much smaller and fainter nebulous object to the west of the comet. The comet was easily visible with 8x42 binoculars as well as with the 20x80s.

The comet was in the constellation Draco. Its rough location at the time of this observation was RA 15hr 57min, Dec. +62 degrees 28min. I estimated the comet's coma to be about 0.2 degrees in diameter. The comet is currently well placed in the evening sky for observers at mid-northern latitudes.

An aurora was visible a few degrees above my northern horizon. The aurora was somewhat brighter (with a small amount of structure visible) around 5:20 U.T. than it was at the time of the comet observation (5:50 U.T.). The aurora never extended very much above my northern horizon and seemed to have little or no effect on the limiting magnitude higher in the sky.

Venus & Saturn - Together

2007-07-02T04:25:00.000Z

Date: 2 July 2007 U.T.
Time: 2:40 - 3:40 U.T.
Telescope: 80mm f/5 (ST-80) refractor
Magnifications: 22x, 24x, 39x, 54x
Seeing: Fair
Transparency: Good
NELM: Bright Twilight
Temperature: +77 F (+25 C)

Venus and Saturn shared the same low to medium powered telescopic field this evening. Venus was a brilliant, white crescent while Saturn appeared roughly half as large and much fainter. At all of the listed magnifications it was possible to observe both planets simultaneously in the same field of view.

Venus was visible to the unaided eye prior to sunset; but Saturn proved difficult in the telescope until after the sun had set. Later, in a darker sky both planets became easily visible to the unaided eye in the western, evening sky.

A sketch was made of the relative sizes and orientations of the two planets, but in order to show both together, as they appeared in the telescope it would be necessary to render the planets as very tiny objects.

The small, portable telescope was set up on my north porch for this evening's observation.

Venus - 19 June 2007

2007-06-20T03:05:00.000Z

Date: 19 June 2007 U.T.
Time: 22:40 - 22:50 U.T.
Telescope: 102mm SCT
Magnification: 72x
Seeing: Poor - Fair
Transparency: Partly Cloudy (thin clouds)
NELM: Daytime observation
Temperature: +86 F (+30 C)

The above is my rough, at-the-telescope sketch. North is up. Preceding is toward the left. Disk details are questionable under the seeing conditions; but the south cusp was suspected to be somewhat brighter than the north. The limb was brighter than the terminator. The planet appeared white against the blue daytime sky.

I went outside around 4:00 pm local time, looked up, saw the Moon, looked a few degrees west of the Moon and spotted Venus with the unaided eye. Afterwards I set up the telescope and made the above observation.

Observational Slow-Down:
Lately a combination of factors have slowed down the frequency of my astronomical observations. Among those factors is increased activity in my other (long neglected) hobby - chess. If my renewed interest in chess continues long enough I may start an additional blog devoted to that interest.

Sunspot - 03 June 2007

2007-06-04T00:01:00.006Z

Date: 03 June 2007 U.T.
Time: 16:53 - 17:22 U.T.
Telescope: 102mm SCT
Magnifications: 40x, 90x
Filter: Baader, white light
Seeing: Fair
Transparency: Scattered Clouds

The above sketch shows the sunspot group (Sunspot 960) that has recently rotated to the earth-facing side of the Sun. Preceding is up and south is to the left in this mirror-reversed view. At times during this session clouds blocked the Sun from view.

For most of the observation the telescope was used at 90x. Later 40x was used for the faculae portion of the sketch.

After completing this observation the view was shared with a guest.

Sharing the View

2007-06-03T22:12:00.000Z

Date: 3 June 2007 U.T.
Time: 3:00 - 5:00 U.T.
Telescope: 13cm refractor
Magnifications: 35x, 90x, 170x, 240x
Filters: #56 and #58 Green (for Venus only)
Seeing: Good
Transparency: Bright and darkening twilight

After many cloudy or otherwise missed nights everything fell into place for a good evening. The telescope was set up on on an equatorial mount with an electric RA drive. The motorized tracking simplified sharing the view with two guests.

Venus was our first target, and for a long while our only target. The seeing was very steady with the refractor -- one of the benefits to using a relatively small telescope. The planet's sharply defined quarter (or 'half-moon') phase was easily visible to everyone present.

The green filters helped cut down the brightness of the brilliant, white planet to a more tolerable level. We took turns studying the planet at 90x. Through the use of questions and answers, it looked like the guests may have been able to perceive some of the subtle markings in the Venusian atmosphere.

Eventually the sky darkened enough for the younger guest to spot Saturn in the twilight sky. We shared views at 35x and gradually worked our way up to 240x. Titan was immediately noticed near the ringed planet. After the sky had darkened a bit more we saw three more of Saturn's moons. The two moons between Titan and the planet, one above the other, were later identified as Tethys (to the north) and Rhea (south of Tethys). Just off the north-following limb of the planet was Dione.

At the higher magnifications the ring was visible in front of the planet. The guests also noticed Saturn's South Equatorial Belt (SEB). Cassini's Division presented a challenge for the guests, but they eventually succeeded in seeing this division between Saturn's A and B rings -- at least on one side of the ring system. The shadow of the planet on the ring system proved to be a bit more of a challenge for the guests.

After Saturn we took a look at the globular cluster, M13 in Hercules. Next was the Ring Nebula (M57) in Lyra. The final object was Albireo (Beta Cygni) -- one of the northern hemisphere's "showpiece" double stars.

Twilight had still not quite ended by the sessions end. Nevertheless, part of the summer Milky Way was seen. We also saw at least one meteor, an airplane and at least one satellite.

Sunspot - 18 May 2007

2007-05-18T19:00:00.000Z

Date: 18 May 2007 U.T.
Time: 17:04 - 17:29 U.T.
Telescope: 102mm SCT
Magnification: 90x
Filter: Baader, White-Light
Seeing: Fair
Transparency: Clear with Haze
Temperature: +80 F (+27 C)

The above sketch shows the general appearance of sunspot #956 -- looking somewhat like a smiling, cartoon alien. North is up and preceding is to the left in this mirror-reversed view.

The thin haze in my sky is most likely from a distant forest or grassland fire. It's been enough to discourage me from attempting deep-sky observing on the past couple of nights.

Thoughts on Observing Venus

2007-05-14T16:22:00.000Z

Despite my involvement in amateur astronomy since the late 1960's, I still consider myself a beginning, visual observer. There is much that I still do not know; and I'm continually learning more. Take Venus for instance:

Back in the late 60's I made observations of Venus using an inexpensive, 60 to 65mm refractor. My observations showed the changing phases of the planet. I was able to see how the apparent size of the planet varied as Venus travelled around the Sun. The planet appeared noticeably smaller when near full, on the far side of the Sun than it did when near new, on the near side of the Sun. Venus was a brilliant, white, featureless planet - excepting only its changing apparent size and phase.

Only rarely since those early observations have I re-visited Venus. I had rarely, if ever, heard other amateurs mention observations of albedo variations on Venus. There seemed little point in observing a planet on which one cannot see surface nor atmospheric features.

This year my attitude toward Venus has changed. The change had its origins in a thread pertaining to the visual observation of Venus in the Usenet group: sci.astro.amateur. Apparently, some people could see a sharply defined (yet, pretty much featureless) planet when they observed Venus through their telescopes, while others could see little more than a bright, boiling blob of ever-changing color.

In the saa discussion, mention was made of the visibility of subtle, atmospheric details that some have claimed to see. So, I decided to start observing the planet on a more or less regular basis with my current arsenal of telescopes and filters - to see what I could see . . .

After experimenting with filters, I found that a green filter (with or without a Moon-SkyGlow filter) seemed to work best on Venus for my eyes. As a result, most of my subsequent Venus work has involved the use of a green filter.

I soon found myself "suspecting" subtle detail in the Venusian clouds; but it took a while before I felt confident enough to attempt sketches of those details. Within this blog I often prefaced references to Venusian details with the qualifier: "suspected". This was because I was not fully convinced that the subtle details that I saw were truly details within the Venusian clouds. When observing near one's limits, other factors can enter the equation. The human eye, for instance, is a far from perfect optical instrument.

As I made more observations, I became more convinced that I was seeing actual albedo variations on Venus. Nevertheless, due to their subtle nature and the less than perfect seeing conditions it has remained difficult to record those variations with a high degree of confidence and/or accuracy.

I take my own Venus observations with a grain of salt. The main reason for this self-scepticism has to do with the subtleness of the suspected details. Observing detail on Venus is not like looking out a window and seeing a tree. It's more like looking out a window on a very foggy morning and "suspecting" a tree. In the case of Venus, atmospheric turbulence (in Earth's atmosphere) causes subtle planetary detail to be visible sometimes and invisible at other times - during the same observing session. It's necessary to patiently study the planet in the eyepiece, waiting for the detail to show itself. It's very much like catching intermittent glimpses of a tree as the fog thickens and thins.

Atmospheric turbulence was noticeably less problematic during my last Venus observation. The subtle Venusian details could be seen more consistently than ever before. Furthermore, I was using my largest telescope (and a green filter). Also, Venus was nearer to Earth and thus appeared larger than it had for my earlier observations. For that observation, I can remove the qualifier; "suspected". Detail was very definitely being seen, and that detail originated within the Venusian atmosphere.

So what about the boiling, colorful blob that some see when they look at Venus?

When conducting a test, the only time I could see color around Venus when using my Newtonian (a telescope type that does not suffer from chromatic aberration) without filters was either when I viewed the planet using an eyepiece that was poorly corrected for chromatic aberration, or when I waited for Venus to settle lower in my sky -- allowing Earth's atmosphere to bend the different colors by noticeably different amounts.

Of course, the "boiling" aspect that some have mentioned is due entirely to thermal effects in the line of sight between the observer's eye and the planet. More specifically, these thermal effects exist either in the air above the telescope, in the air inside the telescope, or both.

Some telescopes are less susceptible to internal thermal effects than others. Some observers exercise more care in avoiding telescope thermal effects than others. Some observing sites are better than others. Certain times of the year may be better than other times for a given location. Venus is not equally high in the sky near local sunset for observers observing from different latitudes. The list goes on . . .

I'm fully convinced that Venus can be an interesting and rewarding planet to observe for those willing to devote the necessary time and effort.

I.S.P. Disappointment & sci.astro.amateur

2007-05-09T21:15:00.000Z

Almost one week ago the newsgroup feed from my Internet Service Provider ceased. It took a few phone calls and a few days to learn what little I now know about the situation.

I've participated for several years, under one identity or another, on the unmoderated Internet Usenet group: sci.astro.amateur. My presence in sci.astro.amateur pre-dates the origin of my website. As a matter of fact, it was discussions on saa that led me to create the website.

Initial contact with my ISP indicated that they were unaware of what a newsgroup was and unaware that they had been providing the feed.

After the passage of several days I was informed that my ISP had been under the impression that they had dropped newsgroups last October! When asked if they were going to turn back on the newsgroup feed, their response was; "No."

Unfortunately, options are very limited in my rural area when it comes to ISPs. It's possible to access Usenet in other ways; but so far I've not found an alternative that I'm entirely comfortable with. So, at least for the time being, I can read postings to saa; but I'm unable to make responses.

Sunspot - 07 May 2007

2007-05-07T21:29:00.000Z

Date: 07 May 2007 U.T.

Time: 16:54 - 17:14 U.T.

Telescope: 102mm SCT

Magnification: 90x

Filter: Baader White-Light

Seeing: Fair

Transparency: Clear

Temperature: +63 F (+17 C)

The above sketch shows the same the sunspot that I've been following for the past several days. North is up; and preceding is to the left in this mirror-reversed view. This sunspot will soon be transferred to the far side of the Sun via the Sun's relatively slow rate of rotation.

Sunspot - 02 May 2007

2007-05-02T19:20:00.000Z

Date: 02 May 2007 U.T.

Time: 16:40 - 17:00 U.T.

Telescope: 102mm SCT

Magnifications: 70x and 90x

Filter: Baader, Objective Solar Filter

Seeing: Fair

Transparency: Thin Clouds

Temperature: +76 F (+24 C)

The above sketch shows the same sunspot as the previous three sunspot sketches. North is up; and preceding is to the left in this mirror-reversed view.

The thin clouds were too thin to be noticed through the telescope as silhouetted forms against the bright sun.

Venus (01 May 2007)

2007-05-02T03:36:00.000Z

Date: 01 May 2007 U.T.
Time: 1:46 - 1:56 U.T.
Telescope: 102mm SCT
Magnification: 150x
Filter: #56 Green
Seeing: Fair to Good
NELM: Sunset - Bright Twilight
Temperature: +68 F (+20 C)

The above sketch shows the general appearance of Venus on this date. North is up; and preceding is to the left in this mirror-reversed view. The region in the neighborhood of the north cusp seemed to be a little brighter than the rest of the planet.

The subtleties of light and shade on Venus are roughly comparable to what one would see when examining a small section of an egg shell. When observing Venus it's not easy to tell exactly where the borders lie between regions of different shadings. Nevertheless, with experience it is possible to detect subtle variations within the Venusian atmosphere.

One of the joys of amateur astronomy is the acquisition of observing skills. Arguably, one might say that much, or even most of what an experienced observer sees when studying an object would go completely unnoticed by a beginner or by a much less experienced observer. If there were few challenges involved in this hobby I would have dropped out long ago.

After completing my sketch I tried using a violet filter. Under bright twilight with the 102mm telescope at 150x the violet filter was found to be too dense. Next I tried a variable polarizing filter. Unfortunately the seeing conditions deteriorated fairly rapidly, forcing an end to such experimentation.

Sunspot - 01 May 2007

2007-05-01T22:31:00.000Z

Date: 01 May 2007 U.T.

Time: 16:25 - 16:40 U.T.

Telescope: 102mm SCT

Magnifications: 70x and 90x

Filter: Baader, Objective Solar Filter

Seeing: Fair

Transparency: Clear

Temperature: +67 F (+19 C)

The above sketch shows the same sunspot that was observed on the previous two sessions. North is up; and preceding is to the left on the mirror-reversed image. A mild wind was effectively blocked by the walls of the "Colosseum".

Sunspot - 29 April 2007

2007-04-29T18:20:00.000Z

Date: 29 April 2007 U.T.
Time: 15:50 - 16:20 U.T.
Telescope: 102mm SCT
Magnification: 90x
Filter: Baader Solar Filter (Objective)
Seeing: Fair
Transparency: Thin (Cirrus) Clouds
Temperature: +71 F (+22 C)

The above sketch shows the same sunspot that was observed two days earlier. North is up. Preceding is to the left (mirror reversed image).

A comparison of the this sketch with the previous sketch will give an idea of how quickly the appearance of a sunspot can change. Even during the thirty minute's it took to make this observation minor changes could be noticed.

Sunspot - 27 April 2007

2007-04-27T19:56:00.000Z

Date: 27 April 2007 U.T.
Time: 18:56 - 19:12 U.T.
Telescope: 102mm SCT
Magnification: 90x
Filter: Full Aperture, Baader, White-Light Solar Filter
Seeing: Fair
Transparency: Mostly Clear with Scattered Clouds
Temperature: +67 F (+19 C)

The above sketch shows the sunspot that was near the Sun's following limb on this date. The view is mirror-reversed. North is up. Preceding is to the left.

A mild wind was blowing during this observation; but the curved wall of the "Colosseum" blocked most of it. Clouds briefly blocked the Sun a couple of times during the observation.

Venus & Saturn with ST-80

2007-04-25T17:21:00.000Z

Date: 25 April 2007 U.T.

Time: 2:31 - 4:42 U.T.

Telescope: 80mm f/5 refractor

Magnification: 105x

Filters: #58 Green, #12 Yellow

Seeing: Good

NELM: Bright Twilight (later 5.3)

Temperature: +45F (+7 C)

Above is Venus as seen with the small refractor from 2:31 until 2:36 U.T. North is up. Preceding is to the left. A 90 degree, mirror diagonal was used, resulting in a mirror-reversed image. A #58 Green filter was also used for this observation.

The planet's phase was slightly gibbous, almost quarter. The sunlit limb of the planet (to the left) appeared to be a little brighter than the rest of the planet. Two darker regions were suspected as shown in the above sketch.

Above is Saturn with Titan to the upper right. This observation was made from 4:22 until 4:42 U.T. As with Venus, north is up; and preceding is to the left. A #12 Yellow filter was used for this observation. (The Venus and Saturn sketches are not to the same scale!)

Visible features include the C-ring where it crosses in front of the planet, the shadow of the planet on the ring system, the Cassini Division (appearing as ill-defined, somewhat darker arcs near the outer edges of the ring system), and the South Equatorial Belt (the subtle, dark 'band' running parallel to the planet's equator (and ring system) in the planet's southern hemisphere.

After observing Saturn I took a look at Earth's Moon, which was near Saturn in the sky. A tremendous amount of detail was visible at 105x. Some of the lunar mountains were casting long, pointed shadows. I was tempted to sketch the crater Cassini; but instead decided to end the session early.

Two Galaxies and a Planet

2007-04-17T19:10:00.000Z

Date: 17 April 2007 U.T.
Time: 1:50 - 5:50 U.T. (with breaks)
Telescope: 30cm Newtonian
Magnifications: 150x (Venus)
160x (M81)
250x (M82)
Filters: Moon-SkyGlow & #58 Green (Venus)
None (Galaxies)
Seeing: Fair to Poor
NELM: Bright Twilight (Venus)
6.5 (Galaxies)
Temperature: +43 F (+6 C)

Venus was observed and sketched near sunset. The planet's gibbous (approaching quarter) phase was obvious. Subtle markings were difficult to pin down due to relatively poor seeing conditions. Nevertheless, I was able to complete a rough sketch.

M81, a bright, spiral galaxy in Ursa Major was observed and sketched at 160x. This galaxy had a small, bright, central region surrounded by a fainter, oval glow. Upon closer inspection one of the galaxy's spiral arms became evident on the north following side of the galaxy's nucleus. Other arms were suspected as glimpses were caught of darker regions within the faint glow of M81's outer regions.

M82 is a bright, irregular galaxy near M81 in Ursa Major. A few brighter and darker regions were seen without much difficulty in this interesting, cigar-shaped galaxy.

Green Venus & More

2007-04-14T19:09:00.000Z

Date: 14 April 2007 U.T.
Time: 1:50 - 2:06 U.T.
Telescope: 30cm Newtonian
Magnification: 150x
Filters: Moon-SkyGlow & #58 Green (simultaneously)
Seeing: Fair to Poor
NELM: Bright Twilight
Temperature: +45 F (+7 C)

The above sketch gives a better idea of how Venus looks when using a Green filter (with or without an MSG filter). In the sketch, South is up and Preceding is to the left. Seeing conditions were a little worse than they have been for most of my earlier observations of this planet. The cause might be related to warmer daytime temperatures. Seeing conditions seemed to have improved later in the night when I targeted other objects.

Using words, the south polar region of the planet seemed to have a bit more white than elsewhere on the planet. A large dusky region was suspected in the mid-southern latitudes. A smaller dusky region was suspected in the mid-northern latitudes. The limb region away from the terminator appeared somewhat brighter than the rest of the planet.

The highlight of this night's observing were my later, deep-sky observations. Seeing conditions improved, and transparency proved to be very good some time after the Venus observation. Careful observations and sketches were made of NGC 3242 (The Ghost of Jupiter) at 250x and NGC 4565 (The Needle Galaxy) at 120x. Both objects were nicely shown by the 30cm Newtonian.

By the time I had completed the above observations (6:07 U.T.) with a break between each, I had grown rather fatigued. At one point I had decided to attempt to stay awake until Jupiter reached my south meridian; but fatigue ended up the winner of that battle and I eventually called it a night.

A Brief Binocular Session

2007-04-13T16:57:00.000Z

Date: 13 April 2007 U.T.
Time: 4:00 - 4:30 U.T.
Binoculars: 20x80 (hand-held)
Seeing: Good
NELM: 6.4 (or better)
Temperature: +29 F (-2 C)

Three relatively bright non-Messier objects were targeted this evening. The first was NGC 2403. This galaxy was very easy to see with the large binoculars. It looked like a small, distinct patch of nebulosity and was more readily visible than many of the Messier galaxies.

Next was NGC 3242 "The Ghost of Jupiter". This object is a small, but very bright planetary nebula. Through the binoculars it resembled a slightly bloated, slightly fuzzy star. The detailed charts in the Uranometria Atlas allowed for easy identification via the surrounding star field.

Last on my list was NGC 4565 "The Needle Galaxy". This well-known, edge-on, spiral galaxy was visible in the binoculars as a small, faint, elongated glow with a somewhat brighter middle.

For whatever reason, I found myself looking in the vicinity of M81 with the unaided eye. I noted the nearby star pattern as plotted on atlas charts. All of the nearby stars plotted in the Cambridge Star Atlas (2nd edition) were visible to the unaided eye. In particular, I noted 24 Ursae Majoris and the unlabeled star between 24 and M81. At times I suspected a tiny, faint glow at the exact spot where M81 was supposed to be.

I'm not positive that I saw M81 with the unaided eye on this evening; but I'll try to remember to look for this relatively bright galaxy from time to time (with the unaided eye) when conditions are favorable.

M 104 (The Sombrero Galaxy)

2007-04-08T17:22:00.000Z

Date: 8 April 2007 U.T.
Time: 5:17 - 5:40 U.T.
Telescope: 30cm Newtonian
Magnifications: 250x and 120x
Seeing: Fair to Poor
NELM: 6.5
Temperature: +22 F (-6 C)

The Sombrero Galaxy is a beautiful object! It consists of a small, bright, central core surrounded by an elongated (east-west), fainter glow. The glow is widest in the central region, growing progressively narrower further out. Just south of the core a narrow, dark, dust-lane was visible running the length of the galaxy. The galaxy's glow to the south of the dust lane was considerably fainter than the glow to the north. The galaxy appeared to be slightly brighter along its western extension than along its eastern extension.

The overall shape of M 104 was similar to that of two saucers with their rims in contact with one another -- viewed edge-on.

A magnification of 250x was used for most of the observation and sketching. Later I dropped the magnification down to 120x. It may have been possible to see the faint, outermost glow of the galaxy a little better at the lower magnification; but details showed up better at the higher magnification.

Venus (08 April 2007)

2007-04-08T16:38:00.000Z

Date: 8 April 2007 U.T.
Time: 1:55 - 2:10 U.T.
Telescope: 30cm Newtonian
Magnification: 150x
Filters: Moon-SkyGlow and #58 Green (simultaneously)
Seeing: Fair
NELM: Bright Twilight
Temperature: +29 F (-2 C)

The gibbous disk of Venus was sharply defined. Suspected, subtle darkenings on the planet's disk were sketched. The planet appeared to have a bright, featureless, narrow rim around (just inside) its limb everywhere excepting the planet's terminator. The largest suspected dusky marking was in the planet's southern hemisphere. A possibly connected, smaller, dusky feature was suspected in the planet's north-preceding quadrant. Two subtle, dark 'notches' were suspected along the planet's terminator. One was near the center of the terminator. The other (slightly larger) notch was a bit more to the north.

It's difficult to be certain of suspected features in the Venusian clouds. The planet appears to be almost without visible markings. The suspected markings mentioned above may or may not be actual features in the Venusian atmosphere.

My typical procedure (and the one followed on this evening) is to set up the telescope prior to sunset after the wall of my open-air observatory is casting a high enough shadow to place the telescope's lower section (containing the large, primary mirror) in shade. Sunlight shining on that section of the telescope might prolong cool-down of the mirror. (The telescope has a built in cooling fan; but I've never felt a need to use it.) The observation of Venus began shortly after sunset, after the telescope had been outside for over an hour.

Venus (27 March 2007)

2007-03-27T03:42:00.000Z

Date: 27 March 2007 U.T.
Time: 1:30 - 1:50 U.T.
Telescope: 80mm refractor
Magnifications: 20x, 40x, 67x
Filters: None, #56
Seeing: Fair
NELM: Bright Twilight
Temperature: +53 F (+12 C)

Tonight's observation was made using a relatively simple, 80mm, f/5 achromatic refractor. Such telescopes are occasionally used by individuals just starting out in amateur astronomy. More experienced amateurs sometimes use such instruments as quick-look, grab-and-go telescopes or even as finders for larger telescopes.

I chose this particular telescope this evening for the following reasons: Predictions called for bad seeing, wind, and increasing clouds. I wanted to see what Venus looked like through a small and relatively low quality telescope on a relatively poor night.

At 20x Venus looked like a tiny blob of bright light surrounded by a substantial, mostly purple glow. Yellow-green light was occasionally also seen around the planet. These colors were due primarily to the telescope's achromatic objective lens. Such objectives fail to bring all colors to the same focus; but often, particularly when looking at much less brilliant objects, this defect can go unnoticed. At 20x the planet's disk could not be made out with any degree of certainty.

At 40x the planet's disk was clearly visible. It was difficult, but possible to discern the planet's gibbous phase. False color surrounded the planet just as it did at 20x. The planet's normally white disk appeared somewhat yellowish due to the 80mm achromat's chromatic aberration.

At 67x the planet's disk was clearly visible; and its gibbous phase was clearly discernable. The wind was strong enough to shake the telescope a little; but it wasn't strong enough to compromise the observation. The false color extended outward from the planet in all directions a distance of at least three planetary diameters. The disk of the planet was only mildly discolored (like it was at 40x).

At 67x with a #56 Light Green filter the planet looked much better. Green was the only color visible with the filter. For all practical purposes the filter effectively eliminated the achromat's false color. The purple glow around the planet was gone and replaced by a much weaker greenish glow. The seeing conditions caused the planet to jiggle a little as if it were made of jello; but the jiggling was quite mild. The planet's gibbous phase was well defined and obvious.

Moon - Unaided-Eye

2007-03-27T03:18:00.000Z

Date: 27 March 2007 U.T.

Time: 1:15 U.T.

Instrument: Unaided-Eye

Temperature: +55 F (+13 C)

As the above sketch shows, a telescope is not always necessary in order to make observations of other worlds. North is up and lunar east is to the right in the sketch.

Predictions called for bad seeing, wind, and increasing clouds; but meanwhile the sky was mostly clear so I decided to skip out on setting up a large telescope and instead make a quick, unaided-eye observation of the Moon. After all, it's often said that one can see more on the Moon with the unaided-eye than one can see on Mars with the aid of a telescope.

Saturn's Moons (25 March 2007)

2007-03-25T21:57:00.000Z

Date: 25 March 2007 U.T
Time: 6:45 U.T.
Telescope: 30cm Newtonian
Magnification: 300x
Seeing: Poor to Bad
NELM: 5.7 (Moonlight)
Temperature: +40 F (+4 C)

I had hoped for (and was expecting) better seeing conditions. Under the circumstances, 3oox was way too much magnification; but I kept looking and hoping for conditions to improve (Clear Sky Clock had predicted improved seeing). In the end, I had to skip the planned Saturn observation and instead record nothing more than Saturn's brightest moons.

In the above sketch a more or less 'generic' Saturn is shown looking much sharper than it actually looked during this session. South is up. Preceding is to the left.

The brightest moon, to the lower left of the planet is Titan. Titan was discovered on this very date in 1655 by Christian Huygens. Proceding clockwise from Titan, the other Saturnian moons are: Tethys, Dione, Iapetus, and Rhea.

After I posted the above sketch I noticed that some of the moons didn't show up as well as I had hoped. Iapetus should be the faintest moon. It's located to the right of Saturn about one ring system span from the rightmost tip of Saturn's ring system. Rhea is about midway between Iapetus and the ball of the planet, but shifted a small distance downward. Rhea appeared to be second in brightness after Titan; but doesn't show up that way in the above sketch.

Tethys and Dione, both to the left of the planet should appear approximately equally bright (but don't appear so in the sketch) -- just slightly fainter than Rhea.

I had tried something a bit different in the creation of the above sketch; but the final result didn't turn out as well as I had hoped. I'll know better next time!

Maskelyne (lunar crater)

2007-03-25T21:32:00.000Z

Date: 25 March 2007 U.T.

Time: 3:19 - 4:05 U.T.

Telescope: 30cm Newtonian

Magnification: 145x

Filter: Moon-SkyGlow

Seeing: Fair to Poor

NELM: 5.6

The above sketch shows Maskelyne, an oddly-shaped, 24km wide crater in the south-central portion of the Moon's Sea of Tranquility.

This is my first lunar observation with the MSG filter. The filter appeared to remove the yellow color from the Moon, creating more of a black and white landscape; but I didn't notice any improvement in visible detail.

Venus (25 March 2007)

2007-03-25T20:01:00.000Z

Date: 25 March 2007 U.T.
Time: 1:30 - 2:30 U.T.
Telescope: 30cm Newtonian
Magnifications: 60x, 200x, 250x, 395x
Filters: none, #47, #38A, #58, MSG
Seeing: Fair (most of the time)
NELM: Bright, then darker Twilight

The phase of the planet had changed by a small, but very noticeable amount since my last observation. The planet is slowly growing in apparent size. Its phase is gradually changing from a fat gibbous toward quarter. Much of the following experimentation with magnifications and filters was inspired by recent discussion on the newsgroup; sci.astro.amateur.

The above sketch shows the general appearance of the planet as observed on this evening. South is up. Preceding is toward the left.

A page full of notes was taken as I experimented with magnifications and filters. I started with a magnification of 60x without the use of any filters. The planet's phase was immediately evident. The disk was well defined. The planet appeared white, devoid of any false color.

Next up was a huge jump to 395x. Atmospheric turbulence became significantly more noticeable. The planet's phase remained easily visible. Some false color ranging from rust orange to blue to gray was introduced by the eyepiece optics in the sky immediately adjacent to the planet's limb. The planet itself remained essentially color-free.

I tried 250x next. The small amount of false color around the planet varied with eye placement. It was evident that this eyepiece had better color correction than the previously used eyepiece.

The ideal magnification for the telescope, object, and sky conditions seemed to be 200x. Once again, the small amount of false color in the sky immediately adjacent to the planet's limb varied with eye placement. The planet itself remained white with no false color. Up until this point in time no filters were used.

For most of the remaining of the session I maintained a magnification of 200x. A #47 Violet filter was tried. The image became steadier. The filter introduced a weak, violet, reflected image that overlapped the image of the planet when the planet was far from the center of the eyepiece's field of view. Otherwise that reflection was not seen.

I prefered the brighter image offered by a #38A Blue filter over the denser violet filter; but the seeing seemed to be a little better with the violet filter. I next combined the Moon-SkyGlow (MSG) filter with the blue filter. A very subtle improvement in the view of the planet was suspected over the blue filter alone.

The blue filter was replaced with a #58 Green filter. Some subtle albedo markings on the planet were suspected. The planet's terminator appeared to darken relative to the rest of the planet.

I removed the MSG filter. With the #58 Green filter alone the subtle detail seemed a little more difficult to detect. It would appear that the combination of the MSG and #58 Green filters may work best for my eyes, Venus, and the 30cm Newtonian.

The MSG filter was tried without any other filters. It imparted a very weak, purple (but almost white) color to the planet. The color was easier to notice with the planet placed out of focus.

By now Venus had dropped lower in my sky -- lower than I've previously observed the planet this year; but I remained curious about all the false color that other's have mentioned when observing this brilliant planet. I lowered the magnification to 60x to brighten the planet in the darkening sky in an attempt to exaggerate any false color. Venus now had a blue glow above its disk and a red glow below. Perhaps the planet had dropped low enough in my sky for Earth's atmosphere to refract the different colors differently enough to notice. Nevertheless, it remained very easy to see the planet's disk and phase despite the planet's much smaller apparent size and much greater apparent brilliance.

My attention was now drawn to the diffraction spikes created by the telescope's spider. In the darker sky it was possible to see that the spikes consisted of a rainbow pattern of color. At increasing distances from the planet, the color in the spikes changed from yellow to orange to red to blue and green. The pattern repeated further from the planet as the light in the diffraction spikes grew weaker. The planet itself remained free from such 'false' color.

Saturn (18 March 2007)

2007-03-18T05:54:00.000Z

Date: 18 March 2007 U.T.
Time: 3:15 - 3:42 U.T.
Telescope: 13cm refractor (full aperture & stopped down to 30mm)
Magnifications: 66x, 80x, 138x, 218x
Filters: Moon-SkyGlow and unfiltered
Seeing: Good
NELM: 6.5
Temperature: +45 F (+7 C)

This session started with a test. Several years ago I made a series of Saturn sketches using the same telescope stopped down to effective apertures of 10mm, 20mm, 30mm . . . 100mm, 110mm, 120mm. At that time I noted that the presence of Cassini's Division could be detected as a subtle shading near the outermost edges of Saturn's ring system with a 30mm aperture.

Some have doubted that observation, so this evening I attempted to duplicate it. I placed a mask with a 30mm circular opening in front of the telescope. Saturn was then studied at 66x and 80x without the use of any filters. Even though the ring system was opened less now than it was several years ago, I was still able to detect (though not as easily as before) the shading near the outer edges of the rings caused by the presence of Cassini's Division. Furthermore, with the 30mm aperture the ring was visible as a darker line where it passed in front of the planet. It was also possible to discern which part of the ring system Saturn's globe was casting its shadow on.

Saturn at full aperture: The 30mm mask was removed and the planet was studied primarily at 218x. I found that I preferred the view without the Moon-SkyGlow filter, so the MSG filter was removed for most of the session.

Five suspected Saturnian moons were sketched, but later it was discovered that one of the suspects was a star. Titan, Dione, Tethys, and Rhea were all positively identified. Tethys was very close to the south-following limb of the planet. Of these four moons, Titan was the only one noted with the 30mm aperture.

Overall, Saturn looked very much as it did when I observed and sketched it several nights ago using a 30cm Newtonian. The larger telescope resolved the Cassini Division better, particularly near the limb of the planet. Saturn's narrow Equatorial Belt, just south of the ring system in front of the planet was more difficult to see with the 13cm refractor. Saturn's South Equatorial Belt was suspected to be double in the Newtonian; but it appeared single in the refractor. (A blue filter was used with the Newtonian observation.)

One probable error in the earlier Saturn sketch involved a dark line adjacent to the north edge of the ring system in front of the planet. That dark line should probably have been the outermost edge of the A-ring itself. Such was the general appearance this evening with the 13cm refractor.

Venus (18 March 2007)

2007-03-18T04:42:00.000Z

Date: 18 March 2007 U.T.
Time: 1:17 - 2:00 U.T.
Telescope: 13cm refractor
Magnification: 218x
Seeing: from Fair to Poor to Bad
NELM: bright twilight
Filters: Moon-SkyGlow, #47, #80A, #23A, #21, #58, #56, #11, #15

This observation began shortly after sunset using only the Moon-SkyGlow filter under Poor seeing conditions. The planet's gibbous phase and slightly shaded terminator were easy to discern. For the remainder of the observations the MSG filter was used in addition to the various colored filters.

At 1:25 I tried a #47 Violet filter, but found the resulting image to be too dark.

At 1:30 a #80A Blue filter was used. The seeing improved to Fair. The limb of the planet (away from the terminator) seemed to be brighter than the rest of the planet. The planet's disk and phase were fairly sharply defined. Hints of subtle shadings were suspected on the planet's disk.

At 1:37 a #23A Red filter was used. The visible details were similar to those seen with the #80A filter.

At 1:39 a #21 Orange filter was used. The planetary limb remained bright. Disk detail became less distinct.

At 1:42 a #58 Green filter was used. At this point in time the subtle, disk details became more distinct than with any of the previous filters. The subtle shadings were sketched.

At 1:46 a #56 Green filter was used. Seeing became suddenly worse, ranging from Poor to Bad.

At 1:50 a #11 Yellow-Green filter was used. Seeing remained Poor to Bad. Nevertheless, the terminator shading was suspected to be enhanced. The disk details may have also been enhanced; but the Poor to Bad seeing made it difficult to be certain.

1:53 a #15 Yellow filter was used. The seeing turned Bad.

1:55 the #58 Green filter was tried again. The seeing appeared to improve. Another sketch was made of suspected disk details. This time a small bright patch was suspected along the north-preceding limb. The other disk details were in good agreement with the earlier (1:42 U.T.) sketch.

Conclusions: The #58 Green filter seemed to bring out the most detail. It's unknown if the addition of the Moon-SkyGlow filter helped or not when used with the various color filters. The 2-inch MSG filter was screwed into the 2-inch star diagonal while the various 1.25-inch color filters were, one at a time, screwed into the eyepiece. It's unknown if any of the filters were responsible for improved or worsened apparent seeing conditions.

The so called subtle disk details may or may not have been actual albedo variations in the atmosphere of Venus. It's easy for the eye to be tricked into seeing such things. Further observations will be necessary in order to draw any meaningful conclusions.

20x80 Binoculars - M51 etc.

2007-03-10T21:09:00.000Z

Date: 10 March 2007 U.T.
Time: 6:30 - 7:50 U.T.
Binoculars: 20x80
Seeing: Good
NELM: 6.5 (mostly)
Temperature: +28 F (-2 C)

The above sketch shows the general appearance of M51, also known as the Whirlpool Galaxy as seen with 20x80 binoculars. The smaller fuzzy spot just above (north of) M51 is NGC 5195.

At sunset my sky remained cloudy. When the sky finally cleared I decided to continue my hunt for Messier objects using the large binoculars. In Messier number order I observed the following objects: M3, M5, M13, M40, M44, M51, M53, M63, M67, M68, M81, M82, M83, M92, M94, M97, M101, M104, M106, M108, and M109. Over the past few months I've observed all of the Messier objects using 20x80 binoculars.

The month of March is sometimes referred to as the Messier month. From some locations it's possible in March to observe all the Messier objects in a single, moonless night. Such an all night session is known as a Messier marathon.

I prefer to spread the observations out over a few months. In this manner I can observe the objects when they're higher in my sky and easier to see. Besides, it can be quite difficult catching some of the objects in March from my latitude. Nevertheless, if opportunity knocks I might be tempted to attempt a Messier marathon.

M83 proved to be the most elusive object. I looked for it at irregular intervals for the last 35 minutes of the observing session. A long, thin cloud hung out over this galaxy for much of the night. Finally, as the Moon was rising I managed to see M83. The galaxy was just a little brighter than the background sky at that time. It's even possible that I was observing M83 through a thin cloud layer.

20x80 Binocular Session

2007-03-09T15:18:00.000Z

Date: 9 March 2007 U.T.
Time: 5:37 - 6:45 U.T.
Binoculars: 20x80 (hand held)
Seeing: Good
NELM: 6.0 - 6.5
Temperature: +28 F (-2 C)

High Humidity and Clouds: A small amount of rain fell during the day prior to this session. The floor of my open-air observatory remained damp. Clouds didn't dissipate until sometime after sunset. Due to these conditions I decided to not set up a telescope. By the time of the observation a fairly thick layer of frost had formed on the porch, etc.

At the start of the binocular session my sky was clear in the west. The rest of the sky seemed to be covered with very thin clouds. Later, conditions improved enough to allow me to see most of the objects that I wanted to observe.

M41 is an open star cluster in Canis Major. Someone had recently mentioned on the newsgroup, sci.astro.amateur that they were disappointed in the appearance of this cluster in their 130mm telescope. I made a response as to some possible reasons, and mentioned that M41 was visible to the unaided eye under a sufficiently dark sky. So, with a clear sky, I decided to pay a visit to M41.

Sure enough, the cluster was a relatively easy object to detect with the unaided eye. Through the binoculars M41 was resolved into numerous individual stars. I found the view to be 'rather nice' despite the cluster's low altitude in my southwestern sky.

Galaxies in Leo, Virgo and Coma Berenices: Next on my agenda were the Messier galaxies in the Virgo region. The above sketch has north up and west to the right. It shows the general appearance of M65 (the galaxy to the right of center), M66 (the galaxy to the left of center), and NGC 3620 (the fainter galaxy north of the other two). Galaxies tend to look like faint,fuzzy stains against the background sky when observed with 20x80 binoculars.

In addition to the three objects mentioned above, I observed the following galaxies: M58, M59, M60, M64, M84, M85, M86, M87, M88, M89, M90, M91, M95, M96, M98, M99, M100, and M105.

Near the end of the session the Moon rose. The high humidity scattered the moonlight, making the sky much brighter than it would have otherwise been.

M 78

2007-03-07T16:01:00.000Z

Date: 07 March 2007 U.T.
Time: 2:34 - 2:54 U.T.
Telescope: 30cm Newtonian
Magnification: 90x
Seeing: Good
NELM: 6.5
Temperature: +43 F (+6 C)

M78 is a bright patch of nebulosity in Orion. Two bright stars and one fainter star were seen within the nebulosity. A fourth star was briefly suspected, but not recorded. The northwestern edge of the nebula was brightest and best defined. The rest of the nebula fanned out south-southeastward like a short, but very wide cometary tail.

Nearby, just northwest of M78 was a fainter, elongated patch of nebulosity, NGC 2067. Oddly enough, I noticed a dark lane between the two nebulous patches before I realized that there had to be a second patch of nebulosity to complete the appearance of a dark lane. This nebula came as a surprise to me. If I had seen it before I had forgotten about it.

A third patch of nebulosity, NGC 2071 was easily seen surrounding a bright star in the same field of view north-northeast of M78.

After looking up M78 in various books and atlases I noted a fourth patch of nebulosity, NGC 2064 southwest of M78. I failed to notice this patch at the telescope; but now that I know it's there I can look for it next time.

Venus (07 March 2007)

2007-03-07T14:48:00.000Z

Date: 07 March 2007 U.T.
Time: 1:28 - 1:42 U.T.
Telescope: 30cm Newtonian
Magnification: 200x
Filters: #80A (Blue), Moon&SkyGlow (Multiband)
Seeing: Poor to Fair
NELM: Twilight
Temperature: +46 F (+8 C)

The above sketch shows the basic appearance of Venus on this evening. South is up. Preceding is to the left. The 'X' shaped pattern was caused by 'spider diffraction.' The telescope's diagonal mirror is supported in the center of the tube by four, thin vanes (the spider). Usually spider diffraction isn't noticed; but on bright objects such as Venus enough light is transferred to the diffraction pattern for the eye to notice.

The fat, gibbous phase of the planet was the only obvious feature seen. During the first half of the observation a #80A filter was used. During the second half of the observation a Moon-SkyGlow filter was used along with the #80A filter. The #80A filter transmits 30% of the incident light. The Moon-SkyGlow filter transmits significantly more light and works like an RGB-Intensifier.

The filters gave the planet a weak, bluish tint. The diffraction spikes had a silver-gray color. The background sky was grayish. A break (gap) in the diffraction spikes was apparent approximately 5 or 6 planetary diameters from the planet.

Part of the west wall of my open-air observatory was lowered earlier in the day in order to allow the telescope to 'see' lower in my western sky. In an earlier attempt to observe Venus with the 30cm telescope the wall had gotten in the way.

Lunar Eclipse

2007-03-04T03:43:00.000Z

Date: 4 March 2007 U.T.
Time: 1:03 - 1:26 U.T.
Telescope: 102mm SCT
Magnification: 34x
Seeing: Bad
NELM: Bright Twilight
Temperature: +37 F (+ 3 C)

The rising Moon was spotted in the trees at 1:03 U.T. -- just nine minutes before the end of the umbral phase of the eclipse. The Earth's shadow along the Moon's eastern limb was obvious in the telescope as well as to the unaided eye.

The seeing was very unsteady. Rapidly moving undulations were in constant motion along the limb as well as over the face of the Moon.

Colors: The Moon was a golden, yellow-orange color outside the umbra. No colors other than shades of gray were noticed near and within the umbra.

Observational Highlights: As occasionally happens in this hobby, I started out with the objective of observing one thing (the final phase of an eclipse) and ended up with a bit more. Due to atmospheric refraction the rising Moon appeared noticeably 'squished'. It appeared shorter along its vertical axis than along its horizontal axis. But of greater interest were the colors (due to atmospheric refraction) hugging the lunar limb. From top to bottom along the lunar limb the colors were: blue, green, yellow, orange, and red. As the Moon rose higher in the sky these colors became less noticeable.

The Penumbra and Clouds: An attempt was made to observe how long the Earth's penumbra could be positively distinguished on the Moon after the umbral phase of the eclipse had ended. Unfortunately, at 1:25:30 U.T. a thin cloud began covering the Moon. Up until that point in time it was possible to distinguish (with telescope as well as with the unaided eye) the effect of the penumbra of the Earth's shadow on the Moon. It seemed ill-advised to continue the observation with the complicating effect of clouds.

Saturn: 25 February 2007

2007-02-26T02:36:00.000Z

Date: 25 February 2007 U.T.
Time: 5:55 - 6:48 U.T.
Telescope: 30cm Newtonian
Magnifications: 250x and 300x
Filter: #80A and unfiltered
Seeing: Fair to Good
NELM: 5.3 (Moon in sky)
Temperature: +17 F (-8 C)

The above sketch shows the basic appearance of Saturn on this night. South is up. Preceding is to the left.

After initial collimation of the truss-tube telescope I pointed the scope at Polaris, increased the magnification to 400x, and used the de-focused star's Fresnel pattern for a final 'tweak' of the collimation.

The scope had been outside for a few hours prior to the session. At the beginning of the observation the seeing was Fair. The sketch was initially made at 250x with the #80A filter.

As the session progressed the seeing improved. I removed the filter and increased the magnification to 300x. At times of steadier seeing the image was quite sharp. Tethys, one of Saturn's moons is shown just south of (above) the preceding (left) portion of the ring system.

Initially, Cassini's Division was not visible all the way to the limb of the planet, but that changed after the seeing improved. Both the preceding and following limbs of the planet were darkened a little. The C-Ring was visible against the background sky as well as against the ball of the planet. The filter may have darkened (increased contrast) of the planet's southern hemisphere belts as well as the C-Ring against the planet. The outer portion of the A-Ring was darkened somewhat and some structure was hinted at. The inner portion of the B-Ring was darkened somewhat.

Some clouds came and went during the observation. The outside of the telescope had attracted a fair amount of frost during the session.

This was my first high magnification planetary observation with the 30cm Newtonian. It's not likely to be the last!

The Great Orion Nebula

2007-02-20T21:19:00.000Z

Date: 20 February 2007 U.T.
Time: 4:20 - 4:50 U.T.
Telescope: 30cm Newtonian
Magnifications: 61x and 155x
NELM: 6.5
Seeing: Poor
Temperature: +24 F (-4 C)

The Great Orion Nebula, also known as M42 is one of the brightest and most beautiful nebulae in the night sky! This large nebula practically fills the field of view at 61x. In its brightest regions it's possible for some people to see color. I noted a weak greenish glow in the brightest parts of the nebula and a hint of red in some of the other areas.

Within the brightest part of M42 is a tight group of four stars known as the Trapezium. At 155x I was able to see a fifth star in the Trapezium without much difficulty. A sixth star was more difficult due to the poor seeing conditions; but it was occasionally suspected near the glow of the brightest member of the 'big four.' On a good night I've seen all six stars with ease while using a considerably smaller (13cm) telescope.

M42 is a very irregularly shaped nebula. It has many curves and regions of widely varying brightness. I used the low magnification of 61x in order to be able to see the entire nebula at once; but it's well worth the time to study individual parts under higher magnification.

M43 shares the field with M42. It's much smaller in size, has a semi-bright star within it, and has the shape of a fat comma. While having separate entrees in the Messier Catalog, M42 and M43 are parts of the same nebula complex.

Before ending the session I swung the scope around to Saturn for a quick look at one of our solar system's real show-pieces. Saturn is always a joy to behold!

Even if I weren't too tired to continue observing I would have had to quite soon due to increasing clouds. As I was bringing the scope, etc. back inside more and more stars were disappearing behind the thickening clouds.

Horsehead Nebula, etc.

2007-02-20T20:32:00.000Z

Date: 20 February 2007 U.T.
Time: 4:10 U.T.
Telescope: 30cm Newtonian
Magnification: 61x
Filter: UltraBlock
NELM: 6.5
Seeing: Poor
Temperature: +25 F (-4 C)

I started out without using the above mentioned filter. NGC 2024 (also known as the Flame Nebula and Tank Track Nebula) was visible near Zeta Orionis. This nebula has a prominent dark lane running through it.

After shifting the telescope slightly to the south, Zeta Orionis left the field of view. The small, bright nebula NGC 2023 was now easily visible surrounding a star.

The next logical step was to look for IC 434 (a faint 'bright' nebula) and the dark notch within it known as B33 -- the Horsehead Nebula. These objects were visible with difficulty. IC 434 was only slightly brighter than the background sky. The Horsehead Nebula has a reputation for being a particularly difficult object to see visually without the use of a specialized (H-Beta) filter. In order to successfully see this object without a filter one must observe from a dark location that's free from the glow of city lights.

I don't have an H-Beta filter; but I do have an UltraBlock filter. The UltraBlock is a multi-layered, interference filter that selectively blocks the wavelengths of some of the more common man-made light sources (as well as some of the natural sky glow) while allowing other wavelengths to freely pass through. I screwed the UltraBlock filter into the eyepiece and took another look.

IC 434 and the Horsehead Nebula were suddenly significantly easier to see! The filter significantly darkened the background sky, but not the light from IC 434. As a result, the nebula became easier to see.

I should add that filters such as the UltraBlock do not improve the visibility of all objects in the night sky. Many objects become more difficult to see when such filters are used. Everything depends upon the wavelengths of light and their relative intensities as emitted by the various celestial objects. Furthermore, the effects of many such filters can vary significantly depending upon one's sky conditions and light pollution situation.

For more information on the Horsehead Nebula the curious reader is encouraged to visit Stephen Waldee's excellent Horsehead Nebula Main Page and associated links at:
http://home.earthlink.net/~astro-app/horsehead/index.html

Limiting Magnitudes, Plans, etc.

2007-02-15T14:18:00.000Z

Date: 15 February 2007 U.T.
Time: 3:00 - 3:40 U.T.
NELM: 6.6
Temperature: -9 F (-23 C)

During the lengthy cloudy spell I revised observing projects, etc. A (new) home-made, square, eyepiece field stop was fabricated that includes a means to more accurately determine angular size as a fraction of the field of view. Refinements were made on a deep-sky project geared toward an all-sky, telescopic survey. Rough plans were drawn up for systematically sketching (mapping) the entire visible portion of Earth's moon.

I'll be as surprised as anyone if I actually manage to succeed in seeing these plans through to their natural conclusions! I'm easily distracted by a bright comet, a well positioned planet, other projects, etc.

I dug up some 'new' limiting magnitude charts that should allow me to make nightly estimates on the limiting magnitudes of my binoculars. I wore red goggles inside a dimly illuminated room for half an hour or so to aid in dark adaptation prior to going outside.

Once outside I used my new charts to determine my Naked-Eye Limiting Magnitude (NELM). Next I repeated the procedure using 8x42 and 20x80 binoculars, both hand-held. I have little doubt that a solid tripod would increase the binocular limiting magnitude. Eventually I'll need to check that out . . .

The limiting magnitude of the 8x42 binoculars was about 10.0. That of the 20x80 binoculars was about 11.4. All values, including the NELM were adjusted for the zenith -- one tenth of a magnitude was added from what was seen in the 45 degree altitude star fields. With practice these values should become more reliable. I hope to eventually correlate the various measurements with one another.

Later I may add telescopic limiting magnitudes figured for a specific exit pupil size (telescopic aperture divided by magnification) to the mix.

I also want to start making better use of filters for the Moon, planets, and deep sky objects; but I think I'm going to need multiple lifetimes in order to accomplish everything!

Happy Birthday Galileo! Galileo Galilei was born on 15 February 1564 in Pisa, Italy. He's known not only for his ground-breaking telescopic observations; but also for his experimental approach that led to the discovery of the pendulum's time-keeping potential, ballistic science, and much more.

The Sun, Mercury & Venus

2007-01-27T02:51:00.000Z

Date: 26 January 2007 U.T.
Time: 18:02 - 19:00 U.T.
Telescope: 13cm Refractor
Magnifications: 80x and 110x
Seeing: Poor
NELM: Daytime
Temperature: +33 F (+1 C)

The above sketch shows a sunspot that has just rotated onto the Earth-facing side of the Sun. North is up. Preceding (west in the sky) is to the left. Both sketches appearing in this post are mirror-reversed. Notice that the spot's umbra appears off-set toward the center of the Sun. Sunspots near the solar limb often show this "Wison effect."

The brighter patches near the sunspot are faculae. Faculae show up best near the solar limb where limb-darkening darkens the surrounding area.

A safe, white-light, solar filter was placed over the telescope's objective for this observation.

The above sketch shows Mercury (to the left) and Venus. North is up. Preceding is to the left. The thin, unlit portions of the planets were invisible; but in the sketches those areas appear darker than the background sky. I decided to depict the planets in this manner after seeing how difficult it was to notice the phases in my previous Mercury - Venus sketch. Venus was a tad bit closer to being full than the above sketch suggests. There's always something that isn't quite right; but usually I don't say anything!

Hercules & Atlas

2007-01-26T02:27:00.000Z

Date: 25 January 2007 U.T.
Time: 21:08 - 22:00 U.T.
Telescope: 102mm SCT
Magnification: 72x
Filters: Polarizing
Seeing: Fair to Good
NELM: Daytime
Temperature: +51 F (+11 C)

The above sketch shows the region around Hercules (bottom) and Atlas. North is to the upper right; and west is to the lower right in this mirror-reversed sketch. This sketch is the actual 'at-the-telescope' sketch. A polarizing filter helped to improve contrast for this daytime observation of the first quarter Moon.

Daytime observations have some advantages over night observations. There's no need to use artificial lighting for note taking and sketching. The temperature is more comfortable; and it's often possible to catch the object at a higher altitude in the sky.

Day observations also have disadvantages: Contrast is lower for lunar features; and care must be taken in regards to the Sun.

Mercury & Venus - Daylight Obs.

2007-01-25T23:24:00.000Z

Date: 25 January 2007 U.T.
Time: 18:40 - 19:08 U.T.
Telescope: 102mm SCT
Magnification: 120x
Seeing: Fair to Poor
NELM: Daytime
Temperature: +45 F (+7 F)

The above sketches show Mercury to the left and Venus to the right. West is up in these mirror-reversed sketches. The phases of both planets were close to full. The terminators (border between day and night) of both planets are to the East (down in the sketches). The terminators were slightly darker than the rest of the limb region on both planets; but more so for Mercury than for Venus. Some subtle shading was suspected on Mercury -- to the northeast. None was suspected on Venus. Both planets appeared to be white or almost white in color.

Venus was considerably brighter and appeared to be about double the apparent size of Mercury.

Both planets were quite small as viewed in the telescope's eyepiece. Both are currently on the far side of the Sun from Earth; and both are currently east of the Sun in the sky.

A note on "go-to" telescopes: Some people might consider a "go-to" telescope to be a necessity for pointing a telescope at planets in the daytime; but observers made daytime planetary observations long before the invention of electronic computers and self-pointing telescopes. None of my telescopes or mounts have the ability to point themselves at astronomical objects. I've found no need for the technology and have managed to do fine without it. I prefer to point my telescopes myself -- even at planets in the daytime sky. For myself, part of the joy of amateur astronomy is 'driving' the telescope myself.

Theophilus - Revisited

2007-01-25T02:40:00.000Z

Date: 24 January 2007 U.T.
Time: 21:15 - 22:08 U.T.
Telescope: 102mm SCT
Magnification: 72x
Seeing: Good
NELM: Daytime
Filters: Polarizing
Temperature: +52 F (+11C)

The above sketch Shows the ring mountain Theophilus which is 100km (62 miles) in diameter. Nearby is the 28km (17 mile) diameter crater Madler. North is toward the upper right. West is toward the lower right in this mirror-reversed view. The approximate location on the Moon is 11 degrees south latitude, 28 degrees east longitude.

I'm somewhat more pleased with this sketch than I've been with my other recent lunar sketches. Sometimes it doesn't take much practice to make a difference; but usually it takes more than the few (lunar sketches) that I've made this year!

I was surprised at the temperature! Several years ago I could expect temperatures in the neighborhood of minus 20 degrees F. for a week or two at some point in the December through February time-frame. Temperatures in the 50s at this time of year are kind of scary! Of course, the temperature could still drop like a rock at any time . . .

Lunar Observation - Atlas

2007-01-23T04:18:00.000Z

Date: 23 January 2007 U.T.
Time: 00:01 - 00:28 U.T.
Telescope: 102mm SCT
Magnification: 94x
Seeing: Fair
NELM: Evening Twilight
Temperature: +37 F (+ 3 C)

The above sketch shows the 87 kilometer (54 mile) diameter lunar crater, Atlas. North is to the upper right. West is to the lower right. The sketch shows the mirror-reversed telescopic view. I'm still not very happy with my lunar sketches; but the only solution is more practice.

My weather this evening was (according to the Clear Sky Clock) supposed to be: Bad Seeing, Poor Transparency, 30% cloud cover, and strong wind; but the sky was clear. So I took out a small telescope for a quick lunar session.

Last night I set up the 30cm Newtonian (or as Ann referred to it: "The Big Gun") shortly before sunset; but the weather worsened and I ended up bringing the frost-covered scope back inside after several hours of waiting. The weather proceeded to improve afterwards; but by that time it was too late. I decided to get some sleep.

Brief Morning Binocular Session

2007-01-20T13:24:00.000Z

Date: 20 January 2007 U.T.
Time: 12:25 - 12:35 U.T.
Binoculars: 20x80 (hand-held)
Seeing: Good
NELM: 6.5
Temperature: +15 F (-9 C)

Observations were made of three Messier objects in this brief morning session. The first was the globular cluster, M68. Next was the "Sombrero" galaxy, M104; and the last was a rather nice binocular galaxy, M83. All three objects were also visible with 8x42 binoculars; but the 20x80s showed them much better.

Comet McNaught's tail: At the start of astronomical twilight I scanned my eastern horizon for any hint of this comet's tail in the morning sky -- just in case. No hint of tail was evident with either pair of binoculars. On the other hand, parts of my eastern horizon, particularly in the southeast, are cluttered by trees that obscure as much as six degrees from view.

On the more casual side I took quick looks at a few additional Messier objects and scanned parts of the Milky Way before ending the session. For all practical purposes I stopped observing around the beginning of astronomical twilight.

McNaught's Tail - 2nd Observation

2007-01-20T04:56:00.000Z

Date: 20 January 2007 U.T.
Time: 01:30 U.T.
Binocular: 8x42
Seeing: Good
NELM: 6.0 - 6.5
Temperature: +27 F (-3 C)

Clouds presented some difficulties this evening. As my sky darkened, transparency seemed to gradually improve over most of the sky; but multiple, small, scattered clouds persisted in the neighborhood of Comet McNaught's tail rays. Nevertheless, I was able to see the rays better this evening than I could yesterday -- probably due to a combination of multiple gaps between this evening's smaller clouds and the absence of the thin, smokey haze that plagued yesterday's sky.

In the above sketch I've rendered the clouds invisible in order to better show the cometary rays. The motion of the clouds over the course of the observation allowed me to effectively see 'through' them -- even though they had grown worse by the end of the session. I don't give up easily!

On Sketching: I may be my own worse critic. The sketches in this blog are all done fairly quickly; and more often than not I make notes on the originals specifying how each sketch can be improved. A quick comparison of the above sketch with yesterday's sketch will reveal some changes that go beyond the raw subject matter. In a very real sense, each sketch is an experiment in sketching. In all sincerity, I hope I never create a 'perfect' sketch. I'm a human being, not a camera. I want to do the 'seeing' myself!

Comet McNaught's Tail

2007-01-19T03:51:00.000Z

Date: 19 January 2007 U.T.
Time: 01:30 U.T.
Binoculars: 8x42
Seeing: Good
NELM: Approximately 6.0
Temperature: +17 F (-8 C)

Comet McNaught's tail was observed above my west-southwest horizon near the end of astronomical twilight. My sky was compromised a little with smoke from a not too distant fire. The thin haze from the smoke could be seen in all directions prior to darkness. I had to walk over some semi-rough terrain to get to my 'good' western horizon. From my regular observing locations nearby trees compromise that horizon.

The sketch was made immediately upon returning indoors. I tried to memorize enough of the star patterns to accurately place the rays from the comet's tail. The known eight degree field of view of the binoculars was used as an aid in making angular measurements. The longest (right most) ray was approximately sixteen degrees in length. Its top extended beyond the top of the dark cloud. The upper ends of the other rays were obscured by the cloud, the bottom of which was about nine degrees above my horizon. The span between the outermost rays was estimated to be about ten degrees at the horizon. Venus (not shown) is just below the horizon about three degrees to the left of the left most ray. Lines have been drawn connecting some of the stars into familiar constellation patterns.

Four primary rays were seen. In addition to the two outermost rays, there was a center pair of rays. Hints of additional rays were seen with increasing frequency to the right of the second ray from the left. The rays were visible with difficulty to the unaided eye. They were much better with the 8x42 binoculars. The approximate azimuth of the center of the ray system along the horizon was estimated as 252 degrees.

At the time of the observation the Sun was approximately seventeen degrees below the horizon directly below the bottom end of the rightmost ray. The comet was approximately twenty-three degrees below the horizon at an azimuth between the left edge of the sketch and the left most ray.

Omissions from my 17 January Posting

2007-01-18T20:05:00.000Z

I intentionally made yesterday's posting brief; but I may have made it too brief! I intentionally omitted my full descriptions of all 51 observed objects; but I also omitted the following:

Zodiacal Light: At 2:00 U.T. the Zodiacal Light was visible from my western horizon all the way up through Andromeda -- on or near my south meridian.

Barnard's Loop: I didn't write it down at the time, nor did I consult a chart at the time; but I noted the Milky Way passing along the left (east) side of Orion. Furthermore, I noted a distinct gap to the right of the main body of the Milky Way, followed by a narrower arc of "Milky Way". Only this arc might not have been part of the Milky Way at all. It might have been Barnard's Loop -- a large arc of nebulosity in the same general area of sky. I've been unable to determine for certain (checking atlases and photos today) if the arc I saw was a part of the Milky Way or if it was Barnard's Loop. At the time I didn't bother training the binoculars on the arc. Hopefully a second observation will clear this up for me. My sky might be clear tonight . . .

Enhanced Night Vision? Two nights ago (17 January U.T.) deepsky objects looked unusually good. I saw the California Nebula with ease. Normally one would conclude that this would be due to improved sky transparency; but I specifically checked my NELM on that night. It was no better than on a typical, dark night. Furthermore, there was even an aurora on that night; though it wasn't particularly bright, nor did it cover a large area of sky.

Approximately 36 hours prior to the night observations I had spent a few minutes looking for Comet McNaught (near the Sun, which was blocked from view) in the daytime sky. I had used binoculars for the search. Might this have resulted in sensitized eyes some 36 hours later? I can recall one similar 'coincidence' several years ago. It's enough to raise my suspicions.

Additional observations and/or experimentation may be necessary to get to the bottom of this mystery.

My Final Omission: This one was intentionally omitted; but upon further reflection I see no good reason not to provide at least some details. During my binocular observations, at one point approximately 6 aircraft flew over within a short period of time. It's uncommon to see any aircraft fly over my location, let alone 6 at once! All were headed in the same direction. All were silent (I was wearing a sheepskin hat with earflaps down). All had a bright (one might even say 'brilliant') white strobe light. I trained the 20x80 binoculars on one of the nearer aircraft. Based upon a small number of much dimmer lights, the aircraft proved to be either nearer or larger than I had anticipated. The body of the aircraft was all but invisible -- most likely black. From the rear, the exiting exhaust looked little brighter than a typical nebula, but bright enough to show up as a somewhat faint, blue-white color. It was not noticeable to the unaided eye (I didn't have my corrective glasses on).

One never knows what one might see from the middle of nowhere on a clear, dark night!

January Binocular Session

2007-01-17T15:20:00.000Z

Date: 17 January 2007 U.T.
Time: 2:06 - 6:17 U.T.
Binoculars: 20x80 (hand-held)
Seeing: Good
NELM: 6.5 or better
Temperature: +22F to +15F (-6C to -9C)

As evening approached, my sky remained clear. Yet, the 'Clear Sky Clock' indicated that clouds and/or poor transparency would prevail. So I refrained from setting up a telescope, and made plans for a binocular session -- just in case the sky remained clear.

Living under a dark sky, I was able to observe a few objects, come back inside, record notes, and allow the binoculars to warm up a little (as a preventive measure against dew and frost formation). The sequence was repeated as often as necessary. Of course, I was always careful to maintain a good level of dark adaptation throughout the session.

All told, I observed forty Messier objects and eleven non-Messier objects. Descriptive notes were recorded for all objects. A few details follow:

The Andromeda Galaxy was stunningly beautiful! The Merope Nebula in the Pleiades was easily visible with a well-defined shape. M33 was large and bright with a hint of visible structure. Even M81 appeared larger than usual, with more of its outlying region visible.

Based on the above indicators of a good sky, I decided to try for the California Nebula. It's rare that I look for this object; but on this night I'm glad I did. I was pleasantly surprised to find this elusive nebula easily visible in the 20x80s. Clearly this was a very good night indeed!

When I went around to the north side of the house at 4:50 U.T. I noticed an auroral glow along the north horizon. The glow was centered on magnetic north. A few minutes later I noted a single, somewhat fat auroral ray extending upward about ten degrees above the horizon. Fortunately the aurora was limited in brightness and extent, allowing me to return to my binocular observations.

About forty-five minutes before the end of the session I noticed a rather sudden onset of frost on everything outside. My final observations were of a few galaxies in Leo. They didn't seem quite as bright as I thought they ought to have been. Decreasing sky transparency was suspected.

Comet McNaught & Mercury

2007-01-14T21:31:00.000Z

Date: 14 January 2007 U.T.

Time: 20:10 U.T.

Binoculars: 25x100 (tripod-mounted)

Seeing: Fair

NELM: Daytime

Temperature: +14 F (-10 C)

The above sketch shows the full 2.3 degree field of view of the large binoculars. Comet McNaught is to the lower left. Mercury is the small 'star' to the upper right. North is roughly up; and west is roughly to the right.

The sky appeared clear at the time of the observation; but ice crystals were suspected in the upper atmosphere. A segment from a large, white halo was visible to the left of the Sun immediately following the observation.

The comet was relatively easy to see; but Mercury, due to its faintness, was much more difficult for the eye to perceive.

I had tried earlier to spot Mercury with hand-held 8x42 and 20x80 binoculars; but those efforts proved unsuccessful. Even with the tripod-mounted 25x100 binoculars, and even knowing where to look for our solar system's innermost planet, it took a few minutes to 'spot' Mercury.

Unrelated Note: Using 8x42 binoculars I managed to watch Comet McNaught set yesterday evening. In a mostly cloudy sky I had a thin strip of partial clearing just above my horizon in just the right location. The clearing was only one-fourth to one-eighth of a degree wide! The setting comet looked much like the sketch I had made earlier, in the daytime, with an 80mm refractor -- only not quite as good!

Comet McNaught - Saturday Morning

2007-01-13T19:13:00.000Z

Date: 13 January 2007 U.T.
Time: 16:05 - 18:45 U.T. (9:05am - 11:45am)
Telescope: 80mm f/5 refractor
Magnification: 24x
Binoculars: 20x80
Seeing: Fair
NELM: Daytime - Very Good Transparency
Temperature: 0 F to 13 F (-18 C to -11 C)

Over the above mentioned time interval I made intermittent daytime observations of Comet McNaught. Weather predictions called for clouds today. Indeed, there were scattered clouds in my sky, but much of the sky remained crystal clear! The top sketch above was made at 16:30 U.T. with the refractor. The lower sketch is based on observations made with 20x80 binoculars from 16:45 - 18:45 U.T.

Even immediately after making the refractor-based sketch, the binoculars revealed substantially more of the comet's tail. From then on I used only the binoculars. The refractor showed a smaller, almost stellar pseudo-nucleus.

Near the end of the time interval I found the comet to be "easily" visible to the unaided eye. It was definitely more easily seen with the unaided eye today than it was yesterday. Either my sky improved, the comet brightened, or both. In my opinion the more important factor was a brightening of the comet.

At the end of the session I was able to compare the comet with Venus, both in the 20x80 binoculars. Both objects were at a similar altitude in my sky. Overall, I had no doubt that the comet was brighter than Venus; but Venus seemed to be more intense. That is, per square arcsecond Venus seemed to be more brilliant; but the comet (even its pseudo-nucleus alone) was 'putting out' more light.

Post Script: 21:00 U.T. I just took another (daytime) look at Comet McNaught. It's fantastic with the 20x80 binoculars! This time the tail was 'obvious' even to the unaided eye! This comet is putting on a fantastic show!!

Unaided-Eye Daytime Comet!!

2007-01-12T20:57:00.000Z

Date: 12 January 2007 U.T.
Time: 20:54 U.T. (1:54pm local time)
Sky Transparency: Very Good
Temperature: +9 F (-13 C)

Earlier today I posted my first daytime binocular observation of a comet -- complete with sketch. Well, I've now managed to see Comet McNaught in the daytime with the unaided-eye!

I went out (TAKING ALL NECESSARY PRECAUTIONS) and spotted Comet McNaught once more with 20x80 binoculars. This time my single goal was to try to detect the comet with the unaided-eye. Knowing exactly where to look (after the binocular observation) was critical to my success. Of course, the nearby Sun was COMPLETELY blocked from view during the observation.

Twice I suspected that I might have glimpsed the comet with the unaided-eye; but finally I was able to maintain the comet in my vision long enough to remove any remaining doubt! The comet's tiny, bright, pseudo-nucleus could be held more or less indefinitely in my unaided vision. Even a hint of tail was suspected!

I hereby declare Comet NcNaught to be a Daytime Comet to the unaided-eye!

Daytime Binocular Comet!

2007-01-12T19:28:00.000Z

Date: 12 January 2007 U.T.
Time: 18:50 U.T. (11:50am local)
Binoculars: 20x80 and 8x42
Seeing: Good
NELM: Daytime! in highly transparent sky
Temperature: +5 F (-15 C)

WARNING!! CAUTION!! NEVER look at or toward the Sun with a telescope or binoculars. If the Sun crosses your field of view eye damage or blindness is VERY likely to occur.

As a practicing amateur astronomer since the late 1960s, I've read much on the subject; and I've accumulated a fair amount of experience. Precautions were taken in today's observation that made it physically impossible for me to catch even an accidental glimpse of the Sun while searching for Comet McNaught in the daytime sky.

With the above caution and qualifications in mind, I searched for Comet McNaught in the daytime sky with the aid of 8x42 binoculars. Initially this search was unsuccessful. I switched to 20x80 binoculars. Unlike my 8x42s, my 20x80s have individually focussing eyepieces. This means that the 20x80s were alreadly 'locked' into focus for objects at infinity (Comet McNaught in the evening sky was the last object I had focused on).

I was surprised not only at the brightness of Comet McNaught as seen in the daytime with the 20x80 binoculars, but also at the amount of detail that was visible. The inner portion of the comet's tail was easily visible in the 20x80s! The comet was a very pure white in color. It looked somewhat like a white feather against the deeper blue sky.

The above sketch shows the comet as I saw it with the 20x80s near 12:00 noon. I estimate that I was seeing approximately 15 arcminutes (maybe more) of the comet's tail -- in broad daylight! The observation was made at 18:50 U.T.

After spotting Comet McNaught with the 20x80s I was eventually able to see it with the 8x42s as well. The tail was also visible in the smaller binoculars.

I tried to spot Comet McNaught with the unaided-eye, but was not successful. I judged the comet as "easy" to see with the 20x80s. It wasn't difficult to see with the 8x42s; but it was difficult for the eye to initially acquire.

A Successful Comet Expedition

2007-01-11T04:05:00.000Z

Date: 11 January 2007 U.T.
Time: 00:21 U.T.
Binoculars: 20x80
Seeing: Good
NELM: Twilight
Temperature: about +35F (+02C)

A growing concern brewed today. Comet McNaught was getting closer to the Sun and growing brighter every day. Would I get a chance to see it again? The weather forecast called for clouds tonight. The prospect for tomorrow looked even worse (no clear skies anywhere nearby). In a matter of days the comet will be too far south to be seen from my location.

Making use of the "Clear Sky Clocks", I checked projected satellite images for cloud cover and transparency in and around my area. Eventually I decided to travel to a semi-promising location in the region around the Montana - Wyoming - South Dakota border.

I quickly tossed into my Jeep a clipboard, one sheet of paper, a pencil, a pen and a flashlight along with 8x42 and 20x80 binoculars. I was soon on the road.

As I approached my targeted area, it began to look like the clouds would increase if I kept driving. So, about 1/2 hour before sunset I stopped about 30 miles short of my original goal. I was on a field-access trail facing west into the Sun.

I was beneath a gigantic V-shaped clearing with its apex near the Sun. Clouds were present to my left and right. A few low, scattered clouds were directly in front of me. Venus was spotted with the 8x42 binoculars, followed by the unaided-eye, prior to sunset. The comet was spotted at 23:37 U.T. (10 January U.T.) with the small binoculars shortly after sunset, higher in the sky than I had ever seen it before. A quick sketch was made at 23:47 U.T. with the aid of hand-held, 20x80 binoculars. I rested both elbows on the Jeep's fender to steady the view.

Some scattered clouds were just below the comet. I hopped into the Jeep and back-tracked about 8 miles to a location from which the comet could be better seen. During the drive I occasionally glanced out the driver's side window at the easily visible, naked-eye comet. I made another quick sketch at 00:04 U.T. (11 January U.T.) Then hopped back into the Jeep and back-tracked a few more miles. Finally, at 00:16 U.T. I stopped for my final observation. A careful sketch was made at this time. It was completed just before a major, low-lying cloud swallowed the comet permanently from view.

My observing locations were on either side of the tiny town of Hammond, Montana on Highway 212. The town of Hammond consisted of only one or two buildings -- or that was all I noticed in my preoccupied state of mind.

The above sketch is based on the final (00:16 U.T.) rough, 20x80 binocular sketch. Based on the 3.0 degree binocular field of view, I estimated the comet's tail to be 1.4 degrees in length. A rough estimate of the comet's brightness placed it at magnitude -2.7 (brighter than Jupiter, but not quite as bright as Venus. The above sketch is oriented correctly in relation to the binocular view.

Comet McNaught's pseudo-nucleus appeared to be non-stellar, disk-shaped, and very bright. It and the inner-most region of the tail took on a very slightly yellow-orange color by the time the final sketch was made. Earlier, with the comet higher in the sky, the only color seen was white -- of various intensities.

The faintest, outermost region of tail was 'imagined' to have a slight reddish color. I say 'imagined' because I'm not convinced that I was really seeing any color there.

The Road Home: On the way home I saw flashing red lights in front of me. As I got closer I saw that those lights were on a tow-truck just off the right side of the highway. Parked perpendicular to the highway, beside the tow-truck, was an 18-wheeler. Nearby was an individual holding a "SLOW" sign.

A little further along the road, down a hill, on the left side of the highway I saw several more vehicles with flashing red and blue lights. Another individual was holding up another "SLOW" sign. I spotted several additional tow-trucks off the left shoulder of the road. Then I saw another 18-wheeler. This one was off the left side of the highway, parallel to the highway, lying on its side. It was facing west, the same direction I was driving.

The highway was clear and dry. I found myself wondering if the driver had gotten distracted by the comet. On the other hand, there were quite a few deer in the area . . .

Anyway, I eventually made it home to completely overcast skies. It started snowing within an hour. My 'Comet Expedition' was a success! I'll feel a little better now if I don't get another chance to see this small, but bright comet.

Comet Update

2007-01-09T14:35:00.000Z

Date: 09 January 2007
Time: 14:11 - 14:16 U.T.
Telescope: 80mm f/5 refractor
Magnification: 24x
Seeing: Bad
NELM: Bright Twilight & Clouds
Temperature: +22 F (-6 C)

My morning sky was partly cloudy with enough clear area to provide some hope of seeing Comet McNaught. The comet was spotted in the small refractor at 14:11 U.T. just as it cleared my local horizon. The eastern sky was already quite bright. Clouds were in the immediate area around the comet. During the five minute observation the comet vanished at least twice behind clouds.

This was my poorest view of Comet McNaught so far. The seeing was bad. Clouds were present in my line of sight; and the sky was so bright that not much tail was visible. I took a few notes; but no sketch was made. The persistent clouds and brightening sky seemed reason enough to cut this session short.

Last night, under a 99.9% (at least!) cloud covered sky I used 8x42 binoculars to look through a solitary, narrow break in the clouds for the comet. Venus made a brief appearance; but nothing else was seen.

From here on, Comet NcNaught drops rapidly lower in my morning sky. This means that on each successive morning the comet will be in a brighter sky, making it increasingly difficult to see. My best chance of seeing the comet in the next few days will be in the evening sky -- weather permitting.

Comet McNaught

2007-01-07T19:57:00.000Z

Date: 07 January 2007 U.T.
Time: 14:05 U.T.
Telescope: 80mm f/5 refractor
Magnification: 41x
Seeing: Poor
NELM: Bright Twilight
Temperature: +20 F (-7 C)

The above sketch is mirror-reversed. West is toward the upper right. South is toward the upper left. The observation was made in the morning before sunrise. This sketch is more accurate than that accompanying my previous comet observation.

The comet was initally spotted in 8x42 binoculars just as it cleared the trees along my east-southeastern horizon. It was very easily visible to the unaided eye at that time.

After completing the sketch I lowered the magnification to 16x and kept an eye on the comet as the sky brightened. In time, the sky became too bright to make out the comet's tail. Even later, the comet's central condensation appeared to shrink due to the increase in sky brightness and/or improved seeing conditions.

I was able to maintain sight of the comet until the last time I shifted the scope (to keep the comet in view). At that point my observing eye was unable to pick the comet out of the bright telescopic field of view. This was two minutes before sunrise!

Comet McNaught should be visible in the early evening sky as well. As a matter of fact, it will probably now be easier to catch in the evening sky than in the morning sky. I would have tried yesterday evening; but my sky was cloudy and the ground was accumulating a small amount of snow.

Theophilus - Lunar Observation

2007-01-07T19:35:00.000Z

Date: 07 January 2007

Time: Centered around 12:00 U.T.

Telescope: 80mm f/5 refractor

Magnification: 65x

Seeing: Fair-Good

NELM: 5.1 or better

Temperature: +20 F (-7 C)

The above sketch shows Theophilus (the large formation) and the nearby crater, Madler. West is toward the upper right. South is toward the lower right in this mirror-reversed view. Some of the surrounding details were very hastily rendered, resulting in a more inaccurate sketch. I really need to start using my larger refractor, on it's sturdier (tracking) mount while I sketch comfortably seated. The at-the-telescope sketch that the above was based on was made while standing. The telescope was on a homemade alt-az mount that was set up on a porch -- not the best of situations! Nevertheless, I wanted to continue with a bit of lunar observing and sketching.

Comet McNaught (C/2006 P1)

2007-01-05T16:57:00.000Z

Date: 05 January 2007 U.T.
Time: 14:00 U.T.
Binoculars: 20x80 (hand-held)
Seeing: Fair
NELM: Bright Twilight
Temperature: +15F (-9C)

Under a partly cloudy sky bathed in bright, morning twilight I searched for and found Comet McNaught while scanning the clear eastern sky with 8x42 binoculars. I described the comet's location to Ann; and she also was able to find and observe the comet using the small pair of binoculars.

The above sketch, correctly oriented in relation to the horizon, comes close to matching the view as seen with 20x80 binoculars. North (toward Polaris) is to the upper left. The maximum length of visible tail was estimated (roughly) to be ten minutes of arc (about 1/3 the apparent diameter of a full moon). The comet's head was bright, somewhat 'fuzzy', and non-stellar in appearance. If it could be observed from a dark sky, this comet would be very easily visible to the unaided-eye; but unfortunately Comet NcNaught is currently too near the Sun.

In the next few days the comet will be moving closer to the Sun, making it increasingly difficult to observe from Earth. A low, clear, transparent eastern horizon are necessary in order to see Comet NcNaught. A telescope or a pair of binoculars might also be needed.