Comet Lovejoy, ISS, Jupiter, and Some DSOs
Posted: 16 December 2011
Thursday, 15 December 2011. Beginning about 1000 hours, I began trying to see Comet Lovejoy, a sungrazing comet, with the naked eye. There was a small chance that it might become visible (magnitude -3 or perhaps even -4 or -5) prior to its closest approach to the sun (about an hour before local sunset). About every hour I tried to see the comet by blocking the sun with various obstructions. There was a brief period of clouds covering the sun mid-afternoon, but they moved on. However, no joy on Comet Lovejoy. As the sun set, I took some photos with the D7000 DSLR, 300mm lens, in the hope that I might capture the comet, but nothing was visible.
I opened the observatory at 1802 MST, 50°F. Checked the telescope alignment with Venus at 77X, and then I began preparations for an upcoming pass of the International Space Station (ISS) that would begin in about 25 minutes. I updated the ISS TLE in the AutoStar and mounted the D7000 DSLR at prime focus + 3X TeleXtender. At 1820 MST, I used Jupiter for a focus test and did a test video recording.
The pass began at 1827 MST. It was a good pass, with the ISS going nearly straight up from the southwest, through the zenith, and disappearing shortly after passing the zenith. Tracking was good for the first half of the pass and I was able to capture a few faint images of the Space Station in the 5 minute 32 second video. The exposure was 1/2000sec, ISO 3200. I am still testing various exposures during ISS passes, and this night's exposure was way underexposed and somewhat blurred from motion. I will use a faster shutter speed and increase the ISO for the next ISS attempt.
This is a raw video frame with the brightness and contrast significanty increased. The ISS is visible on the right. This full-frame image shows the ISS scale at the 8" f/10 prime focus + 3X TeleXtender.
This is a cropped and further edited image from the above video frame:
After the ISS pass was over, I did some Jupiter observing. Four moons were visible at 77X but seeing was bad. Humidity was high at 54%, temperature 44°F. I switched to 206X and added a moon filter, which helped. Some details were visible in the cloud bands.
At 1853 MST, I started a tour of some DSOs that were discussed in an article in the January 2012 issue of Sky and Telescope magazine. I viewed IC1805 and IC1848, both diffuse nebula, at 77X. I added the O-III filter on both nebulae, but the view was better without the filter. As it turned out, I should have used less magnification. I'll do that on a future session. The other DSOs mentioned in the article were too faint for a 8" telescope.
At 1919 MST, I returned to Jupiter. Seeing was still bad. The Great Red Spot was just rotating into view, as seen at 77X. It was more difficult to see at 206X + moon filter. I switched to 133X + moon filter, which provided a better view. (I am still very happy with the new JMI MicroFocus. It makes fine focusing, especially during periods of poor seeing, easy.)
At 1936 MST, slewed to M1, the Crab Nebula, and viewed it at 77X and 133X. Nice object. I also viewed it at 206X; it was faint, but using averted vision, I could just see some details in the structure.
At 2000 MST, the humidity was going up, now at 58%. A breeze was coming up as well. I decided to close up for the night.
Closed the observatory at 2005 MST, 43°F.
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