Deep Into the Virgo Cluster

[Knight of Clear Skies]

(I'm posting this in the astro lounge rather than the imaging section as I'm hoping people can advise me on what I've captured, feel free to move it mods if you think somewhere else is more appropriate.)

Here's a quick image of part of the Virgo Cluster I took in the early hours of April Fools' Day, shot with a Canon 200mm lens at f2.8 on a modded Canon 100D, from Caradon Observatory, Cornwall. The field of view is about 6.5 by 4.5 degrees.

(40 minutes of data in 1 minute unguided subs, with darks and flats applied.)

Markarian's Chain is at the bottom of the image (although unfortunately I've chopped off the massive bruiser with the death ray, M87). The spiral on the left is M100 and the other prominent one above the centre is M99. Here's a plate solved version, using nova.astrometry.net.

Converting to black & white, inverting and stretching gives this:

Can be viewed at full resolution here (5184 x 3379 px).

Here's a full resolution crop of the M100 region (481 x 400 px).

It's quite a deep image, the faint extensions to the spiral arms are showing up clearly, as are the satellite galaxies NGC 4323 & NGC 4328. For comparison, here's an ESO image taken with a 1.5 metre scope.

This got me wondering just how many galaxies are in the image above, so I started hunting around on the web. Here's the same region on Google Sky, which I think uses data from the Sloan Digital Sky Survey (it's about 90 degrees clockwise from my image). Just in this slice of sky, a little over 1% of the total image, there are at least a dozen identifiable galaxies. Here's part of it matched with Google Sky:

Many of these aren't shown by the plate solver, I think it just shows objects from the Messier, NGC and IC catalogues. I've tried some searches on Simbad but some of them don't show up on there either. There must be hundreds of galaxies in the full image, or well over a thousand if we include ones that aren't distinguishable from stars. It's worth emphasising, this was shot with a low-end DSLR, taking 60 second unguided exposures.

I'd love to get a better idea of how deep this image really is, the limiting magnitude and the most distant object. Any suggestions would be much appreciated. I've put the stack up on Dropbox if anyone would like a play with it, it's the autosave from DSS but one of the colour balancing options may have been set.

FInally, I wonder if I've also captured any minor planets in this field? The subs were taken between 1:10 AM and 2:00AM on the 1st April. How would I go about checking this please?

[Stu]

Hi,

Cracking images, nicely done!

I'm wondering whether @Martin Meredith may be your man for this? He lurks over in the video forum mainly I think, and maps very faint galaxies so may be able to help.

Stu

[symesie04]

Nice image with or without the bruiser. Yes i suspect there are some very distant galaxies in there. How many subs were taken?

[Chris Wales]

Super DSO imaging and derective work, some very usegul links as I want to look into this region, many thanks for sharing,

Chris

[Gina]

Amazing!  Great image   Well done   Gives me some back some enthusiasm to get back into imaging

[laudropb]

Very nice image. There is so much there I would not know where to start.

[barkis]

Not in the wrong place in view of the reason you stated.
It's good to see such fine images being produced on SGL, and this Image certainly fits  the bill.   Educational too, which is a plus.
As Gina stated, quality like this serves to Inspire, and give impetus to others with ambitions to be AP's.
It's taking time, but  the Forum's 'Picture of the Month' Competition wil be resurrected in the very near future.
It is being delayed somewhat, but it will happen .

 

[Gina]

'Picture of the Month' Competition will be another encouragement to get back into imaging   I'll look forward to that

[kirkster501]

Great stuff!  Fabulous picture, plate solve and detective work!

[Astrobits]

I have had a quick look with my favourite planetarium prog - Xephem - and marked a few stars the indicate your pic is limited to approx 19th mag:

M100.tif

 

Nigel

 

 

 

[Knight of Clear Skies]

Thanks for the thoughts everyone.

On 4/29/2016 at 10:23, Stu said:

Hi,

Cracking images, nicely done!

I'm wondering whether @Martin Meredith may be your man for this? He lurks over in the video forum mainly I think, and maps very faint galaxies so may be able to help.

Stu

Excellent suggestion, I've seen some of his images of ultra-distant objects. Looking at his posting history I found this thread, his Pretty Deep Maps look ideal for the job. It has stars down to mag 18 and galaxies to mag 20+.

On 4/29/2016 at 10:39, symesie04 said:

Nice image with or without the bruiser. Yes i suspect there are some very distant galaxies in there. How many subs were taken?

It's 40 subs of 1 minutes each.

On 4/29/2016 at 11:08, Gina said:

Amazing!  Great image   Well done   Gives me some back some enthusiasm to get back into imaging

Good to hear.

7 hours ago, Astrobits said:

I have had a quick look with my favourite planetarium prog - Xephem - and marked a few stars the indicate your pic is limited to approx 19th mag:

M100.tif

 

Nigel

Thanks very much, I'll take a look at Xephim.

[Piero]

This is a superb work! Thanks a lot for sharing this! As mentioned above, this is not just imaging, but also a very educational thread! 

[dph1nm]

If you go to the Sloan website they have an interactive viewer where you can click on an object and it will tell you its magnitude

http://skyserver.sdss.org/dr12/en/tools/chart/navi.aspx

NigelM