Ngc 5033

[Jim McMillan]

You don't see this one all that often. It's pretty dim for my setup. I spent a number of nights imaging this, throwing out a lot of subs because of passing clouds. The seeing was actually pretty good each night though. In the end, I ended up with 82 subs x 10 min (13.67 hrs). ACP performed flawlessly throughout.

Jim

[Russell Archer]

Hi Jim

That's a beautiful image
With 13+ hours of imaging I can see how the signal-to-noise ratio is excellent.

Did you have to do anything special to bring out the faint spiral arms and dust lanes (there's lovely detail in the image)?

Likewise, although I've never tried to image NGC 5033, I imagine that the core is pretty bright compared to the spiral arms. Did you do anything to prevent the core being over-exposed?

And is that NGC 5005 showing dimly at the left edge of the image?

I'm really taking your approach to taking lots subs to heart. I can really see the benefits. Or at least I am in theory - we never seem to get more than 2 nights a month free from cloud in London

Russ

[Jim McMillan]

Thanks, Russ. I'll try to answer your questions:

Did you have to do anything special to bring out the faint spiral arms and dust lanes (there's lovely detail in the image)?

Likewise, although I've never tried to image NGC 5033, I imagine that the core is pretty bright compared to the spiral arms. Did you do anything to prevent the core being over-exposed?

The first step is to have a lot of data. The more data you have, the more the faint stuff will be visible. Dealing with a bright core and faint galaxy arms, I guess there are 4 tools that I try: DDP in MaxIm, DDP in CCDStack, Curves in MaxIm, and Curves in PhotoShop - and use the one that produces the best results. For this particular image, I found I liked DDP in CCDStack best, plus a little touch-up in PhotoShop. To emphasize the dust lanes, I used "sharpen" in CCDStack (surprisingly, deconvolving didn't produce very good results) plus selective "unsharp mask" in PhotoShop.

And is that NGC 5005 showing dimly at the left edge of the image?

No, NGC 5005 is outside the FOV and should be close to the same brightness as NGC 5033. This is an unknown galaxy (at least unknown to me) as it isn't identified in SNP.

I'm really taking your approach to taking lots subs to heart. I can really see the benefits. Or at least I am in theory - we never seem to get more than 2 nights a month free from cloud in London.

If the target is pretty high up in the sky (which NGC 5033 is), I'll take as much as 7 hrs per night on one target - 3 1/2 on each side of the meridian. I realize the sky gets pretty thick 42 degrees from the meridian, but that's a compromise I'm willing to make to get more data.

I actually started this image during the full moon and imaged whenever possible over about 12 days (5 nights of imaging - rare in Cleveland this time of year). I got as few as 0 usable images in a night (thin clouds) all the way up to 39 (maximum I tried). This final image represents 3 nights of images (39 + 33 + 10). I didn't use any of the original "full moon" images (36) as they didn't add anything other than raising the background level.

Hope this helps.

Jim

[Dick Berg]

A really wonderful image, Jim. Nice work.

Here's a link to SIMBAD and the clickable map for this region of the sky:

http://simbad.u-strasbg.fr/simbad/si...ound&radius=12

If you click it, it should open properly.

You'll easily recognize NGC 5033. At "8:30" near the left edge is an icon that looks like a pacman. Click on it, and SIMBAD will show you what that object is, and provide all the references it has available - which is not much.

SIMBAD is a wonderful reference if you want to know more about almost any object.

[Russell Archer]

Hi Jim

Thanks, as always, for taking the trouble to explain your approach and techniques.

It's interesting that you use MaxIM, CCDStack and Photoshop to get the effect you're looking for.
I'm reasonably comfortable now with Photoshop curves and so on. I've also had a try with PixInsight, but the lack of documentation, coupled with a non-standard interface makes it hard going.

Thanks again for sharing the image and your technique!

Dick: Thanks for the pointer to SIMBAD - if I'm reading it right, it looks like that little 'smudge' is a galaxy called 'NGP9 F269-0543901' :-)

Russ