The Sun, Mercury & Venus

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

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.

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

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

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

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

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

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

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

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.