M31 Andromeda Galaxy Double Data!

[Stub Mandrel]

More than really, up from 22 1-minute subs to 49 out of 52 stacked. The nosie level has noticeably dropped and the dust lanes are getting better defined. I can't resist the challenge I will have to try and add another hour to this.

[Scott]

why don't you bite the bullet and add another 3-4 hrs  . the only thing better than good data is more good data

[DougM43]

Wow that is a superb image

[laudropb]

That image is coming along very nicely. Good detail coming through.

[The Admiral]

I'd be real pleased with that Neil. I must have go at it a bit later in the year, when it becomes better placed for me.

The only trouble with increasing the exposure time is that the noise levels only drop as its square-root, so a case of diminishing returns.

Ian

[kendg]

Mo data, Mo beddah

[Ruud]

It's a beautiful image! I hope you have plenty of clear skies for the extra data you plan to add.

Looking forward to the next version!

[wimvb]

Very nice framing on this one.

I agree with the others: more data. Even if returns diminish, there still are returns. Another 150 frames at 60 sec is still just 2.5 hrs. With a little luck that is doable in a good night.

 

[Stub Mandrel]

So many targets, so little time!

I have tweaked a few more dark lanes out, but  I need to fiddle more before I'm content.

[Rodd]

Add some longer subs to bring out the dust lanes--use the short subs for the core. Looking good

[Stub Mandrel]

I'm nervous of going over 60 seconds and losing too many subs...

I've had another go, pushing the data a bit harder and the outer dust lanes do appear but unfortunately if you look closely there is a stacking artefact that becomes visible as the two sets of frames don't 100% line up and the faint detail from the dark site subs isn't as obvious in the parts of the image solely from other site. I need to be more careful, but I will try and get another hour or two.

[Rodd]

That is looking even better.  Lots of detail in there.   Not sure how to address the stacking artifact.  The more subs you add from the non dark site, the less they will stand out I think.  Are you not guiding? Is that why you hesitate to exceed 1 minute?  Guide scope and camera combo can be had for a few hundred $--probably less.

[Stub Mandrel]

10 minutes ago, Rodd said:

Guide scope and camera combo can be had for a few hundred $--probably less.

Guiding is the next big contract away :-)

[wimvb]

It won't help with this stacking artefact, but a tip for future sessions. Line up your camera with the RA and DEC directions. You can easily do this by putting a bright star in one corner of the camera viewfinder/sensor and moving the mount in RA. Rotate the camera until the star moves parallel to the edge of the viewfinder/sensor when you move the mount in RA. I find this the only sure way to combine images from several sessions.

[Stub Mandrel]

I normally keep teh camera 'horizontal' aligned with RA, but M31 needs to be aligned across the diagonal!

[wimvb]

I see. Yes, it's a nuisance when large targets aren't aligned in the sky properly.  

You could try marking the orientation on the focuser and camera body with a small piece of tape or something.