NGC2264, Christmas tree, Cone and asteroids (478) Tergeste and (4162) SAF

[Ginge]

Hi all!

I've been bogged down in work for way too long, but have finally managed to gather some photons and process an image. Not exactly off-the-beaten-track to put it mildly, but I've never had a go at NGC2264 before so here's my try. My processing skills are noticeably rusty and it seems I've managed to get a posterization effect in the fainter parts of the nebula. I'm suspecting this stems from the fact that this was my first attempt with MultiscaleMedianTransform... Anyway, excuses excuses, here it goes:


Larger version here: http://farm9.staticflickr.com/8391/8629754326_11e3094e34_o.jpg

I was lucky to catch two asteroids from the main belt aswell. The mag 13.3 (478) Tergeste is the streak in the upper left corner, 80km in diameter and approximately 2.6 AU away. Just right of center you can see another streak which is (4162) SAF, dubbed after Société Astronomique de France, a 23km in diameter, mag 15.7 asteroid, 1.75 AU away.

Cheers!
Ginge

[Jan]

Hi, I would say lovely image but it seems to me improperly focused. Normally, you should never have the difraction spikes like a double cross. Actually also the star discs look a little bit larger. Do you use Bahtinov mask for focusing?

[Ginge]

I do, yes, always bahtinov-mask. This is a problem due to flexing in the thin metal around the focuser I think. It is evident when I look at the stars through the OA guider: when the scope is pointing one direction the stars are fine, pointed another direction they are elongated. It's a real pain in the b**t and I just ordered a pair of Parallax rings to try to fix the focuser. The plan is to drill holes in the rings and bolt them to the focuser. I'm hoping it will work, otherwise I'll have to look for a different scope.

Best regards,
Ginge

[Jan]

Actually I had the same problem, and as you say you will probably end up with a new scope. I have f2,9 and you can see every single little deviation from ideal focal plane. But actually what could solve the problem is the change of the whole tube itself and buy the carbon tube as part e.g. from TS in Germany - it is hand made and much more solid than any of the commercial chinese (or even Orion UK..) tubes, but also you will not have to refocus so often during the session due the termal contraction of the optical system. No worries about fitting everything to the tube, small imperfections can be compensated with collimation.

[Ginge]

That is very interesting Jan. I was looking for someone who could make me a CF tube a couple of years ago but the only one I found who made secifically for telescopes, was out of business. So TS does this you say? Do they drill holes for fastening the primary, the secondary and focuser swell or do they just make the tube?

G

[Jan]

Private message regarding the tube, lets let others comment on your picture:-)