IYA2009, Venus, new Barlow, & Turkeys

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

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

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

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

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

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

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

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

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

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.