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Arp 61 still a dud :-(

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#1 Rick J

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Posted 18 November 2012 - 05:12 PM

Arp 61/UGC 3104 falls under Arp's category for spiral galaxies with high contrast companions on an arm. It is located in the constellation of Eridanus. While redshift puts the main galaxy at about 440 million light-years there's no redshift measurement for the companion that I could find. So there's no way to tell for sure that it a companion though it appears likely. Many other galaxies in the image have approximately the same redshift. All are labeled with the catalog name and distance indicated by the redshift in the annotated image. If they are all members of the same group, as appears likely, most of the distance differences are likely due to motions of the various galaxy as they orbit around the group's center of gravity. The apparently nearby MCG +00-12-053 has no redshift data I could find. I assume it is part of the group. UGC 3105 to the east appears to be the most massive galaxy in the group. It's redshift distance is 400 million light-years. Being so massive it likely is rather near the core distance of the group. It is classed as S0-. Arp 61 is Sa.

The nasty star in the lower right corner is 51 Eridani at magnitude 5.2.

This is a retake as the original was awful. Unfortunately, this try wasn't any better as to detail but the color data wasn't quite as cloud damaged.

14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

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#2 lambermo


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Posted 19 November 2012 - 03:36 PM

It may not be very colourful but it is still a nice group to me.
Thanks for posting

#3 Rick J

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Posted 19 November 2012 - 11:56 PM

By dud I meant the very poor resolution. Fall has nights of very good seeing but they can go to bad in one frame. That's what happened to this frame. I started with 1.6" seeing but by the second frame it was 3.3" and even worse after that ending up at 4.5". Same thing happened the first try. This year has been no better so went with this as the color was better but seeing the same -- lousy.


#4 bill w

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Posted 20 November 2012 - 01:16 PM

depth awesome as usual, regardless
nice catch

#5 J.P.M



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Posted 20 November 2012 - 03:39 PM

I second to Bill, awesome!

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