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First Light M13 Orion 200 SPX

Started by Fay, May 25, 2009, 20:19:21

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Fay

This was 24x180 secs, plus darks, modified Canon 350D, MPPC, guided PHD, stacked DSS.

Have posted this although I have a problem somewhere. The stars are all elongated. This is the full frame. Still work to be done

It is healthier to be mutton dressed as lamb, than mutton dressed as mutton!

Ian

well that middle bit is fantastic, but you're right, there's something messing with your stars. You were talking about yor coma corrector playing up?

I'd also like to know where those extra diffraction spikes have come from. Did you add them manually, we all know how popular they are  :twisted:

I wonder if you've got a pinched primary (or did you pay for it???), it looks a little like astigmatism...

Fay

Good grief Ian, a pinched primary!! I did nothing to it, should it only have one set of diffraction spikes on the two main stars? Perhaps this will point the way to the cause of the problem
It is healthier to be mutton dressed as lamb, than mutton dressed as mutton!

JohnP

Not bad Fay - but definitely something weird somewhere... elongation is all in different directions... Whats a CCPC?

John

Fay

It is healthier to be mutton dressed as lamb, than mutton dressed as mutton!

JohnP

OK - I understand now... thks - John

MarkS

Fay,

That's a good globular cluster in spite of your elongated star problem.  It's a lovely subject for a first light - that scope is giving a useful field of view at high magnification.  You have not burnt the core out, which is good.

It is possible that those elongated stars could be a problem with the stacking - do they appear on the subs?  If the stars in the subs are not elongated then it is DSS that is having a problem with aligning the subs.

Oh, and you've also caught at least a couple of background fuzzies.

Mark

Mac


Ian

that's a good question from Mark. Do the subs have all those diffraction spikes?

Mike

Nice image Fay.

I think Mark might have hit the nail on the head. It looks like there is a slight rotation between frames and the stacking software is not allowing for the rotation. Do you do a two star alignment first on the subs?
We live in a society exquisitely dependent on science and technology, in which hardly anyone knows anything about science and technology. Carl Sagan

Fay

The individual subs are the same, will have a look at spikes. Should there be just 4 spikes each on the two larger stars?

It is healthier to be mutton dressed as lamb, than mutton dressed as mutton!

Ian

what there should depends on the optical assembly. However, it's distinctly odd that the right hand side star appears to have more spikes than the left hand star...

Tony G

Great image Fay, and by the way I like the spikes.  ;)

Tony G
"I'm normally not a praying man, but if you're up there, please save me Superman." - Homer Simpson

Rocket Pooch

Its not pinched optics or the MPCC the elongation is not consistent, odd, Fay I can check the spacers for you this weekend and we can then look at the scope  if I had to put money on it I'd say its the camera moving around a bit.

Its probably a mixture of MPCC spacing and the focuser.

Nice middle bit.

Fay

thanks Chris. I ordered some spacers yesterday. To me it looks like it is the same in the cluster as well
It is healthier to be mutton dressed as lamb, than mutton dressed as mutton!