by Paul LeFevre
(For those who don't like to read reports, new images are at: http://www.slip.net/~lefevre/mx7c/mx7c.htm)
I went out Saturday afternoon to Little Blair Valley, a desert observing site in the Anza-Borrego Desert State Park and about 65 miles from my house. A group of TAC-South regulars were meeting there, along with a crowd from OPTAS (Oceanside Photo and Telescope Astronomy Society).
I was about the 10th to arrive, and took up a spot in the sand somewhat away from the main group so I could image without complaining about anybody's lights. Besides the 10" LX200/ST-80 imaging setup, I brought along my 12.5" dob for viewing while imaging. I was glad I did :)
OPTAS has a very eclectic group of people in it -- there were some hard-core observers, some dedicated imagers, and some very casual astronomers, some of which started a bonfire shortly before dark (really, they did!). For the first part of the evening I wasn't sure if the seeing was bad or if bonfire smoke was messing up my images! It turned out to be a little of both. Anyway, while the bonfire was up I did a drift alignment, and by the time I was ready to go, it was out.
My target list was long and varied, so I would mostly locate a target for imaging, focus and compose, then start a bunch of images going automatically, which generally gave me 30 minutes or so at the dob while pictures were accumulating. I was mainly going after old friends on the Messier list on the dob, since I hadn't used it since last September, and I had two new eyepieces (an 18mm Radian and 15mm Panoptic) to try out on it. M42 looked better than ever with the medium power/wide fields I got in the new eyepieces, so I spent time poking around Orion. It was a Horsehead night in more ways than one -- I got a good image of it, and several of us were able to see it visually in a 16" and two 12.5" scopes with H-Beta filters! First time I'd ever seen it visually, and thanks to Bob N. and Curt W. for the use of their scopes & filters.
As the night wore on, the temperature dropped considerably, and we had something very unusual for this dry, desert location -- humidity! At midnight the temperature was 27 degrees, and humidity was 66%. By 1 AM, some of the scopes were dewing up, and the dew would quickly turn to frost. It became a challenge to keep oneself warm and keep the scopes dry and frost free, and I made more than one trip to the car's heater to warm up despite my clothing and numerous chemical heat packs. The humidity made it feel colder than it was, and it was cold enough!
After one such session in the car from 2:45 to 3:30, I went over to the idle LX200 and punched in NGC 5139, Omega Centauri. The scope didn't complain that it was below the horizon, and slewed over to it. As it was moving, I looked over and saw that the big cluster was visible naked-eye, about 20 degrees above the Southern horizon, as a fuzzy star. And what a view! I quickly set the imaging scope to taking pictures of it, while moving over to my dob (and Curt's dob as well) for more leisurely views. The cluster filled the FOV in the 18mm Radian, and was amazingly steady for being so low. This was the best view I'd had of it since seeing it much higher in the sky last winter in the Philippines! Almost by accident Curt and I found Centaurus A, just up from Omega, and quite plain in binoculars...ah, the advantages of southern latitude :)
I also spent time poking around the galaxy clusters in Leo, looking at M108, 97, 101, and 51 in and around Ursa Major, and running the chain of open clusters in Auriga and Gemini. It was fun to use the dob again, and realize I still could find most of the Messiers without finder charts -- GOTO hasn't completely spoiled me!
Got some good images as well. Check out the link at the top of the report. I sacked out about 5:45 AM until 8:00 or so, and rolled home to a hot shower to thaw out my frozen body. A great night!
It was nice to finally meet Curt in person, and the TAC-South company was thoroughly enjoyable as always, despite the cold. Some fun!
p.s. I still have a few images to process, of galaxy clusters in Leo. I'll do another image posting later...