Arp 157 (NGC 520)

  Arp 157 is a member of the Arp's class Disturbed with Interior Absorption.  The Atlas note is "note segment in NE direction."  I believe that he actually meant the NW direction, and was referring to UGC 957.  It can be seen in all the images but best in the color image below.  I imaged this object several times over a number of years before getting an image I considered acceptable.  It is much more difficult than it looks because of the extreme brightness range.  My color image could certainly be improved but I was happy with it as a first attempt.

The primary is NGC 520 and the faint companion NNW of the primary is UGC 957.  Although extremely difficult to detect, the loop of material nearly connecting them, running from the SW end of 520 almost to 957 can be seen in the color image.  If I did not know it existed, I would have assumed it was just noise.

Click on the color image below to see the full field.  There is an asteroid track SE of Arp 157 and I decided to leave it there.  Also note the very blue "star" between the similar pairs of stars just SSW of the tail.  This is actually a quasar, 01231+034.  It is marked in Kanipe and Webb, and in Megastar.  There is an even brighter one almost at the center of the galaxy, but it is lost in the glare.

Atlas Image              

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