I didn't get home from work until about 2:45 AM on Tuesday morning, and it was a clear but very moonlit, hazy night (there was also, possibly, still high-altitude smoke over Indiana). The Moon was a bright Waning Gibbous, about two and a half days past Full, shining in Pisces. The bright, murky sky made 2nd magnitude stars very difficult to see with the naked eye, and anything dimmer impossible. In fact, only 1st magnitude stars or brighter were obvious!
Even though I was tired, some quick calculations earlier on Monday had made me aware that this morning I had a great chance of observing the "Mare Crisium Sunset Ray." I hadn't actually seen it since observing it twice in 2008, and I'd never photographed it (since I've only had the digital camera since Christmas 2009). So I had the 10" f/4 set up outside by 3:25 AM; the first time I'd had it out, I think, since last April! I pointed it at the Moon and went inside to grab the camera.
Lunar Colongitude at 3:30 AM (7:30 UT Sept. 1) = 122.53°
Lunar Colongitude at 3:45 AM (7:45 UT Sept. 1) = 122.66°
I first went outside from about 3:35 AM - 3:44 AM and I was able to snap 5 images of the whole Moon using 39x power and 42 images using 78x. These were downloaded into Folder #67 in the Nikon Transfer Folder on my laptop. While at the eyepiece, looking to the northernmost part of Mare Crisium, I was encouraged because it looked like the "sunset ray" wasn't too far away from being complete.
Before I was finished, a lot of very thin cloud bands moved into the sky and "dulled" the Moon. I wasn't sure if I was going to get a chance to get in a second observing session.
Below is the best image of the whole Moon obtained during the first session outside. 39x using the Nikon Coolpix L20 camera pressed up against the eyepiece, handheld. 3:45 AM (7:45 UT Sept. 1). Lunar Colongitude = 122.66°
Lunar Colongitude at 4:30 AM (8:30 UT Sept. 1) = 123.03°
Lunar Colongitude at 4:45 AM (8:45 UT Sept. 1) = 123.16°
After downloading and looking through the first batch of photos, I went outside again to find that the thin cloud patches that had been drifting through the sky were gone, so I had a second session of photo shooting between about 4:30 AM - 4:45 AM. During this time I snapped 50 photos using 78x. These ended up being downloaded into Folder #68 in the Nikon Transfer Folder on my laptop.
I should point out that in spite of the hazy (maybe smokey) atmosphere and the humidity in the air, the Seeing conditions tonight were excellent! The images through the eyepiece were very steady with just some shimmering now and then. And several of the camera shots were very clear.
Below is one of the best photos I obtained during this second session outside. 78x and again I took it with the Nikon Coolpix L20 camera handheld to the eyepiece. 4:34 AM (8:34 UT Sept. 1). Lunar Colongitude 123.06°. Below this is an "extreme blowup" of the same photo to show the "sunset ray" near the center, which was now clearly visible! I'd finally captured it!
After this second session, I packed everything up for the morning to get to bed and get ready for another workday. There was dew on the telescope tube and dew cap, but I hadn't had the scope out long enough for this to really be a problem. Singing night insects were chirping, whirring, clicking, and buzzing all around me in the mild, moist night air. This was a very productive night of observing and imaging!
4:00 AM Conditions: Temperature = 72°F, Dew Point = 67°F, Humidity = 84%, Wind = Calm, Pressure = 30.09".
(See next entry for more information about the Mare Crisium "Sunset Ray.")
No comments:
Post a Comment