This Astrobin Debut Object is located 480 million light years away in the constellation of Aries at a declination of +13 degrees. This object was classified by Dr. Arp into the category of Galaxies – Narrow Filaments.

This object consists of 3 galaxies – the blue spiral (LEDA 200206) at top, the yellow spiral (UGC 2320) below it, and the yellow elliptical (MCG+02-08-014) at the bottom. Each galaxy spans about 100,000 light years. The bright object, just to the right of the two spiral galaxies, looks like a star to me.

The highlight of the image is the beautiful tidal star stream tail which streams up and away from the middle galaxy. It is shocking to me that the stream seem to brighten as it moves away from the galaxy, in both my image and Dr. Arp's. I do not understand why it would brighten as it becomes more distant from the source.

The big question is - what is interacting to create the tidal star stream? The natural conclusion is that the 2 close spiral galaxies are interacting with each other, but instead I believe that it is the 2 yellow galaxies (spiral and elliptical) which are interacting to create the star stream. Why? 3 reasons:

1. The distance estimates to the 2 yellow galaxies are identical, while there is no distance estimate to the blue spiral.

2. A wide faint star stream bridge connects the 2 yellow galaxies.

3. The disk structure of the blue spiral looks surprisingly undisturbed to me.

So I believe that long star stream is due to interaction between the 2 yellow (spiral and elliptical) galaxies, and that the blue spiral galaxy just appears to be close to the yellow spiral galaxy because of our line of sight.

Dr. Arp did not weigh in on this conundrum, although the fact that he kept the elliptical within the frame of his image suggests to me that he also thought it was part of the interaction here. Interestingly, his only comment on this object is that he thought that the star stream originated from the star, but clearly in my image that is not the case.