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PatrickGilliland

Abell 1656 - Just for fun/interest - How many Galaxies?

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Seeing was so poor I gave up trying to 'image' last night and shot 3 hours data on Abell 1656 (for no reason other than interest) that should be enough galaxies for this season then :)   Heres 500+ galaxies all in one shot.  

Abell 1656 Cluster.pngAbell 1656 Cluster Annotated.png

 

Not going to win any prizes as seeing was shocking once again, but an interesting use of the time, went exploring and forgot about the imaging.

Maybe an imaging challenge for a bit of fun.  Who wants to raise my 563 galaxies :) ?

Paddy

 

Edited by PatrickGilliland
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Great stuff Paddy. The sheer number of galaxies out there is mind boggling especially with the latest estimates in the visible universe hitting the two trillion mark now!!

Pete

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Exploring the skies can be enjoyable and makes a change from targeting the most photogenic DSOs, possibly we don't see enough of this kind of thing.

41 minutes ago, PatrickGilliland said:

Maybe an imaging challenge for a bit of fun.  Who wants to raise my 563 galaxies :) ?

I have a possible contender, which is just a quick and rough image with a 200mm lens and DSLR of part of the Virgo cluster.

26102592963_f7209fb236_h.jpg

I did some digging and I'd estimate there are somewhere between a few hundred and a couple thousand galaxies here, although many are indistinguishable from background stars. I found at least a dozen in the area around M100, which is less than 1% of the total frame.

26101093154_8a427fc423_b.jpg&key=707345e

Of course, some of the background 'stars' in your shot may also be galaxies. I tried plate-solving my image on astrometry.net but I picked up a lot that it wasn't showing me.

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1 hour ago, theo said:

Great stuff Paddy. The sheer number of galaxies out there is mind boggling especially with the latest estimates in the visible universe hitting the two trillion mark now!!

Pete

 
 

 

55 minutes ago, Knight of Clear Skies said:

Exploring the skies can be enjoyable and makes a change from targeting the most photogenic DSOs, possibly we don't see enough of this kind of thing.

I have a possible contender, which is just a quick and rough image with a 200mm lens and DSLR of part of the Virgo cluster.

I did some digging and I'd estimate there are somewhere between a few hundred and a couple thousand galaxies here, although many are indistinguishable from background stars. I found at least a dozen in the area around M100, which is less than 1% of the total frame.

Of course, some of the background 'stars' in your shot may also be galaxies. I tried plate-solving my image on astrometry.net but I picked up a lot that it wasn't showing me.

 

The trick is how many can you 1. Resolve and 2. Identify.  There is likely 1000-2000 identified galaxies in this image if I could have gone deeper.  Hitting 500+ of resolvable galaxies was a good benchmark. 

Of course, if you wish to frazzle the gray matter a little more - say Hi to QSO HB89 1256+280 (Catchy name!). Subject to calculations it has a distance of 10.3 to 12.3 Billion years!

2017-02-06_19-42-09.jpg

If you factor in poor seeing and the sheer distance the luminosity and EMR energy of this QSO is very difficult to comprehend.

1 hour ago, cardigan wearer said:

No swearing allowed so just, wow.

Considering all the above I have reverted to swearing :) best explanation I can provide!

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Great! I love these Galaxy cluster shots, food for thought how huge the universe really is. The Quasar is a nice bonus. 

Too bad making images like this is nearly impossible from my light polluted location.

Regards,

Pieter

Edited by pietervdv

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Very cool Paddy. Humbling to see so many in one small FOV.

Tom

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2 hours ago, pietervdv said:

Great! I love these Galaxy cluster shots, food for thought how huge the universe really is. The Quasar is a nice bonus. 

Too bad making images like this is nearly impossible from my light polluted location.

Regards,

Pieter

 

Well i took the view that seeing was too poor to really image so just pointed at this and tried it out.  Was quite surprised with what it found.  OK it not a great AP image but still interesting.  If you are not worried about the finer detail etc I think this could be an interesting little past time on poor seeing nights.

I would give it shot and see what Happens.  You might be surprised.

31 minutes ago, Tom OD said:

Very cool Paddy. Humbling to see so many in one small FOV.

Tom

 

Seemed like a good use of time.  Of course the fine detail is lacking and probably could get more on a clear night, nonetheless an interesting use of time on a night where data would have normally hit the trash can!  

Something I may well investigate further when average seeing in UK.

Thanks for interest and comments.

Paddy

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Yes, there are lots of ways to explore the night sky, it's not all about deep and intricate imaging (although, of course, I'm certainly in favour of that too).

On 06/02/2017 at 20:02, PatrickGilliland said:

The trick is how many can you 1. Resolve and 2. Identify.  There is likely 1000-2000 identified galaxies in this image if I could have gone deeper.  Hitting 500+ of resolvable galaxies was a good benchmark. 

The plate solving software I tried wasn't giving me catalogue references for many of the galaxies in my image. There is Academic software available that can analyse images and separate stars (point sources) from other light sources algorithmically, I was talking to a postgrad from the University of Exeter about it. I was hoping that it would separate the galaxies out in my Virgo Cluster image and give a true count, but we couldn't get it to work for some reason.

If anyone wanted to maximise the number of galaxies in an image I'd have thought the Virgo Cluster would be a good target, as it's the nearest large cluster and there isn't much dust in that direction. Hitting it with a pretty short focal length might work best.

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4 hours ago, Knight of Clear Skies said:

Yes, there are lots of ways to explore the night sky, it's not all about deep and intricate imaging (although, of course, I'm certainly in favour of that too).

The plate solving software I tried wasn't giving me catalogue references for many of the galaxies in my image. There is Academic software available that can analyse images and separate stars (point sources) from other light sources algorithmically, I was talking to a postgrad from the University of Exeter about it. I was hoping that it would separate the galaxies out in my Virgo Cluster image and give a true count, but we couldn't get it to work for some reason.

If anyone wanted to maximise the number of galaxies in an image I'd have thought the Virgo Cluster would be a good target, as it's the nearest large cluster and there isn't much dust in that direction. Hitting it with a pretty short focal length might work best.

 

Might have a look at that then, what academic software are you referring too btw?

Paddy

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I suspect they may be referring to something like imstar in IRAF. Been a long time since I've played with IRAF though - needs a bit of work to get going from memory (it's Linux/Mac software). Then you'll need to play a bit with imstar parameters...

Nice image - I do like the deep faint fuzzy bits :)

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On 08/02/2017 at 13:08, PatrickGilliland said:

Might have a look at that then, what academic software are you referring too btw?

Paddy

I can't remember now, but I'll ask when I get the chance. We weren't sure if my stacked data somehow ended up non-linear (I was using DSS to generate a FITS file) or if there was a problem with the odd stars the 200mm lens produces. I'd love to get something like this working, as another way of exploring my images.

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5 hours ago, Knight of Clear Skies said:

I can't remember now, but I'll ask when I get the chance. We weren't sure if my stacked data somehow ended up non-linear (I was using DSS to generate a FITS file) or if there was a problem with the odd stars the 200mm lens produces. I'd love to get something like this working, as another way of exploring my images.

Cool - possible the stack dropped co-ordinates etc.

4 hours ago, niallk said:

WOW!

Brilliant thread :thumbsup::happy7:

 
 

Thanks Nial

4 hours ago, Barry-Wilson said:

This perspective really places humanity in context . . mind boggling to try and comprehend.

Sure does - if I think about too long start to come over all "Chief Inspector Dreyfus" :) 

Edited by PatrickGilliland
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