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.
30 September 2008
29 September 2008
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.
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.
27 September 2008
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.
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.
14 September 2008
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.
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