I haven't been posting a lot lately, largely because a lot of the really quick updates go on Facebook these days. Despite all this, I've been doing a reasonable amount of observing lately. A few weeks ago I had an especially clear night where I could just see the largest dust lane in M31, the Andromeda Galaxy, in the 12.5" scope from the back yard. That was the first time in quite a while I remember doing that.
Here's an image from three days ago (June 29, 2009). This is a full-sized crop of the original. I've tweaked the image slightly (grayscaling to improve chromatic aberration, and a touch of unsharp masking), but the effects are cosmetic; you can still see the same details in the original. The smallest craters clearly visible near the terminator are less than 10 km across: for example, you can see Hyginus A, at 8 km, and it's clearly more than just a couple of pixels). Not bad for a $250 optical tube and a $250 compact non-DSLR camera. It's definitely better than the first few views of the Moon I got through a $3000 telescope 25 years ago!
It's been a quiet few months thanks to rainy weather here in northern Colorado.
June 29 was the first day in 3 months that I got more than a quick look at the sky. As a result, it was more of a "summer showpiece" sort of night, full of big bright things like the 1st-quarter Moon, globulars like M13 and M3, and bright nebulas like M57 and M27.
Saturn, which I'd hoped to observe more in the spring, is finally on its way out; I saw it briefly, but only very low, with already poor seeing made worse by the altitude. I was hard pressed to see any moons besides Titan and Rhea, and no details on the disk itself.
I did get a few quick photos through the 100mm refractor:
Gliese 581 is back in the news, since it apparently has a medium-sized planet in its habitable zone. We have no way of knowing yet if it actually supports life, but if there are intelligent beings there, and they look in the general direction of Orion, they'll notice that one star is peculiarly radio-noisy:
Finally got a few shots in the 100mm scope (24x telescope magnification, time: 1/100 sec. at f/4.5, approximately 10x zoom on the camera itself). Each of these was reduced in size by a factor of 4, whereas last night's image is a 100% crop. The larger image scale does make it clearer just how thin the crescent really is. Unfortunately, Venus was very low and so the seeing was rather poor; the final image quality isn't a whole lot better than with just the camera itself.
Last night, I spent all my observing time on Saturn with the 12.5" Dob, mostly with a 7mm Nagler (227x). This year, the rings are edge-on or very close to it. At the moment, they have opened up slightly, so I could just barely see the (normally very prominent!) dark space between rings and planet. There was a subtle darkening across the planet where the rings crossed; I'm not entirely sure whether it was ring shadow, a cloud band, or both.
I finally took the 12.5" Dobsonian for a spin the evening of March 3, after several months of using only the 100mm refractor (mostly as an astrophotography platform). Since it doesn't have a drive, the Dob's not much use for astrophotos, except of really big, bright things like the Moon:
First quarter moon. 12.5" reflector, 57x, FZ28 1/125 sec at f/4.5
First quarter moon, with a little extra zoom (about 4x) on the camera itself. 12.5" reflector, 57x, FZ28 1/60 sec at f/4.5