First attempt at Virgo Cluster

[old_eyes]

Blessed with a relatively clear night and a long weekend, I thought I would have a try at the Virgo Cluster area and Markarian's Chain.

There was a fair amount of sky-glow, and the view was a bit hazy from time to time, but I got an image centred on NGC4438 based on the following setup:

• Canon 1000D unmodified
  
• Equinox 80ED Pro
  
• CG5-AS GT mount
  
• ST80/Atik16ic/PHD Guiding - autoguiding
  
• 24 x 300 sec subs at ISO 400
  

21 of these subs stacked in DSS, Dynamic Background Extraction and histogram stretch in PixInsight. I did not do any more porcessing as I was interested in how many galaxies I could detect and did not want to process out anything faint.

Working from an inverted BW image and using CdC and Unimap (to plate solve), I managed to identify:

• M84, M86
  
• NGC4305, NGC4306, NGC4351, NGC4367, NGC4388, NGC4402, NGC4413, NGC4425, NGC4431, NGC4435, NGC4438, NGC4440, NGC4446, NGC4447, NGC4458, NGC4459, NGC4461, NGC4468, NGC4473, NGC4474, NGC4477, NGC4479, NGC4506
  
• IC794, IC3256, IC3258, IC3280, IC3291, IC3303, IC3305, IC3311, IC3315, IC3331, IC3344, IC3349, IC3355, IC3363, IC3382, IC3386, IC3388, IC3393, IC3445
  

For a grand total of 46 galaxies.

It is not a very aesthetically pleasing image; there is too much noise, something went awry with the dark frames (may have another bash with some new dark frames), and I did not do any flats. But from the sheer blast of being able to identify so many galaxies in such a rich field with simple gear, this has to be one of the most satisfying images I have taken so far!

One of the best things is that NGC4440 (towards the bottom of the image right under the lefthand of the two big galaxies (M86)) can clearly be seen to be a face on barred spiral in the original image. I think it has a magnitude of about 12, but sources seem to differ.

If I can work out how to label this sensibly, I might re-post.

old_eyes

[Whippy]

That's a cracking field of view, Markarian's chain and more!

I think if you neutralized the background it would help a lot, there's a lot of colour there.

Tony..

[old_eyes]

Oops!

Posted coulour image upside down!

old_eyes

[old_eyes]

That's a cracking field of view, Markarian's chain and more!

I think if you neutralized the background it would help a lot, there's a lot of colour there.

Tony..

Thanks Tony - I need to get much better at sky backgrounds. They always seem to give me trouble, and I know that many others are getting better images with thei Canon 1000D's. I always seem to end up with noise that interferes with the data I want to keep. Not sure what to do next to neutralise the background.

old_eyes

[Whippy]

I'm pretty sure there's a routine for neutralizing the background in pixinsight, I don't use it so I can't say for certain though.

There's a routine for it in gradient xterminator, which is a plugin for photoshop, or there's the method I've used occasionally which is select the background and just de-saturate it. It's a fudge but it looks a bit better!

Hope you don't mind, but I quickly de-saturated the background in photoshop to show you what it'll look like.

Tony..

[old_eyes]

I'm pretty sure there's a routine for neutralizing the background in pixinsight, I don't use it so I can't say for certain though.

There's a routine for it in gradient xterminator, which is a plugin for photoshop, or there's the method I've used occasionally which is select the background and just de-saturate it. It's a fudge but it looks a bit better!

Hope you don't mind, but I quickly de-saturated the background in photoshop to show you what it'll look like.

Tony..

Definite improvement. I'll have a play with that. I used Dynamic Background Extraction in PixInsight, but I haven't used the Background Neutralisation tool yet. Too many tools to learn!

old_eyes

[ollypenrice]

Exciting and remote part of the sky!

There is Background Neutrailzation in PI. I know what you mean about not stamping on the faint stuff so I think BN might be a safer bet than DBE. BN, I think, just works on the colour, not the luminosity. I find it an absolute godsend even with a dark sky and good flats. Harry has a tutorial on BN.

Olly

[old_eyes]

Thanks Olly - I'll roll back to the stacked image and try background neutralisation in PI. I have all Harry's tutorials, I just keep forgetting stuff in the gaps between image processing sessions

old_eyes

[old_eyes]

Hi

I reprocessed the image with better matched darks and some more frames that were taken with a meridian flip.

Then I used more gentle stretching with Dynamic Background Extraction, HDR Wavelets and ACDNR in Pixinsight.

I think the result is somewhat better. I don't think I can get much more out of the data.

old_eyes