Sunday, December 30, 2007

Obsessed ...

I have since July 2004 a Celestron Advanced 20cm Newton GoTo Telescope. It's a marvellous scope for visual astronomy. It's the kind of scope I recommend without any doubts to everybody for deepsky observations. Due to the short focal length (F5) it's less suitable for planetary observations. With this scope I was able to complete the Herschel 400 list in December 2007.

A 20cm scope is indeed good for hunting many deepsky objects. You probably need something like 10 years to observe all feasible objects with a 20cm scope. But except a rather short list of objects there are not a lot of them with details to see. You will see spiral arms on M51 (under a perfect sky like in the Provence). I managed to see a glimpse of a spiral arm of M33 under rural Belgian sky, and there are a few galaxies where a dust band is visible. There are quite some globulars which are impressive. Idem ditto for nebulas like the Orion, M27, M76. And honnestly the Veil nebula is impressive. But the truth is that most galaxies are seen as a little smudge with sometimes are brighter core.

So like a lot of deepsky fanatics, I've been caught by aperture fever. A few years ago I had the chance to look through a 60cm dob. The image of the Eskimo nebula at 600x is still present on my retina. Several observations with a 16" and 18" confirmed the fever.

After some research, and based on great experience from fellow observers & friends I decided to go for an Obsession. Most of those fox have an Obsession, going from 15" to 20" and they are all enthusiastic about their material. The views are impressive. The next decision was the aperture. 15" is a bit too small (it's less than 40cm). 20" becomes heavy and is more tedious to install, so the decision is to go for an 18" (45cm). As I have a goto on the 20cm Newton (I admit I'm not good in star hopping) I wanted to continue to have this comfortable option. So it will be an 18" with Argo Navis and Sky Commander.