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12.5" Dob out of hibernation and hunting Herschels

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

More after the break.

Of course, after the Moon, Saturn was the standout object of the night. Unfortunately, only 3 of its brighter inner satellites were visible, since several were in transit or eclipse. Under good conditions, I can easily see 5, and with the rings almost edge-on, Mimas ought to be visible (if very dimly), making 6 at times. I've easily seen Iapetus in the past, so if I can see Mimas, I'll be up to 7 satellites.

For deep-sky observations, I saw the galaxy M82, which holds up quite well in moonlight, the faint cluster NGC 2158 near M35 (as well as M35 itself, of course), and the bright planetary nebula NGC 2392 in Gemini. These three objects are all part of the Herschel 400 list. A few years ago, I started a project to observe as many of these as possible from the back yard -- light-polluted enough to be a challenge, but with telescopes large enough (then 10", now 12.5") to make it reasonable.

The project went dormant before long (real life intervened frequently!), but I'm gradually reviving it. At the moment, my Herschel 400 list has at least 91 entries (maybe a few more if I go through some of my older observations), with 33 seen from an urban or suburban backyard location. Based on past experience, the Herschel 400 clusters and nebulas will be fairly straightforward, though some nebulas might need a filter. The Herschel 400 galaxies will definitely be a challenge, but I have already seen 6 or 7 galaxies in Markarian's Chain, several smaller and dimmer than most of the Herschel entries, from my backyard. I expect most of them will be visible, at least on Moonless nights. The next few months should bring in lots of them!

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