A short but unexpected EAA session

[AKB]

With the full moon fading, I decided yesterday (Oct 3) to swap out the Quattro and Ha imaging, dusting off the C9.25 Hyperstar, intending to do colour imaging with a QHY8-L.  But the forecast was not good and after an afternoon of connecting up cables, balancing, testing, ... I unscrewed the camera and Hyperstar from the OTA and stored it away again.  Much to my surprise, and a little annoyance, looking out at 10pm I saw a most wonderful sky, with the Milky Way visible.  So I dashed out again, but not wanting to faff around with too many cables, I selected a mono Ultrastar camera.  Needless to say, balancing needed a bit of adjustment, and I didn't try too hard.  There was also a bit more breeze than I thought.

Starting around 11pm, the session was cut short after 45 minutes when suddenly, and I do mean suddenly, the sky became opaque.  I didn't see any clouds blowing in, they just appeared spontaneously.  Completely uniform cover over the whole lot.  The stars just went out.

The Ultrastar gives about a one degree FOV on the Hyperstar, so here's a comparison of single one-minute subs and short stacks, processed subsequently, alas for just two targets, both with no filters:

• Pacman, 9 x 60 sec – not a patch on my recent 1 hour Ha!
• M33, 10 x 60 sec – always a difficult target, I find.

I think the Hyperstar needs some fettling.  I have not done any collimation on this setup yet.

 

 

 

 

 

[RobertI]

These are great captures, the star clouds in M33 are wonderful. The Ultrastar + Hyperstar is a powerful EAA combination. So the first is the capture as viewed on the night and the second is post processed? What software do you use to capture and view? I would have thought that with Starlight Live you would be able to adjust your live 'live' images and get close to the quality of your post processed images?

[AKB]

1 hour ago, RobertI said:

So the first is the capture as viewed on the night and the second is post processed? What software do you use to capture and view? I would have thought that with Starlight Live you would be able to adjust your live 'live' images and get close to the quality of your post processed images?

Thanks, I was pleased with M33 too.  Yes, the first in each pair is as viewed live, the second is processed.

I would have used StarlightLive (which I love, but wish it worked for other cameras, or wish I had a larger StarlightXpress camera) but I had spent the day working with the QHY so captured with Nebulosity and PHD, which guided and dithered – something I think you can’t do with StarlightLive.

[Owmuchonomy]

That M33 has come out extremely well. Just to be clear, is that with the Hyperstar connected?

[AKB]

32 minutes ago, Owmuchonomy said:

Just to be clear, is that with the Hyperstar connected?

Yes.  These are all Hyperstar images.  In the case of the M33 stack, it’s 10 one-minute exposures.  That’s what you get for F2.3 with a 9.25" aperture.  The collimation is particularly bad in one corner, but I’m hoping that can be addressed.

The Ultrastar is, of course, a small-chip, uncooled CCD.  I’d be quite interested to try this with a small, cooled CMOS camera...

[Owmuchonomy]

5 hours ago, AKB said:

Yes.  These are all Hyperstar images.  In the case of the M33 stack, it’s 10 one-minute exposures.  That’s what you get for F2.3 with a 9.25" aperture.  The collimation is particularly bad in one corner, but I’m hoping that can be addressed.

The Ultrastar is, of course, a small-chip, uncooled CCD.  I’d be quite interested to try this with a small, cooled CMOS camera...

Yes, me too. I have two CMOS cameras but not cooled. I don’t have Hyperstar for my 9.25 though.

[RobertI]

8 hours ago, AKB said:

The collimation is particularly bad in one corner

Bad? You clearly haven’t seen some of my images! ?