Object name: M065SN

Designation(s): M065SN, SN 2013an, M066,

M65 is part of Arp 317 which also includes NGC 3628 and M 66. I imaged them individually several years ago. On March 21 a type II supernova blew in M 65. As most of you know I've been imaging all the Arp galaxies I can reach from my 47N latitude. Over the years several have had supernova go off in them. I've gone back to catch them with the supernova. So wanted to add this one to the list but the weather hasn't cooperated. Finally, on April 2 (UTC), it did. I also managed to fit M 66 into the field as well. Conditions were forecast to be poor for seeing but at least I could get color data. Turned out the seeing was better than forecast so I was able to get it in one night. We did have ground fog which didn't help the color. Blue really was hurt so I took 4 rounds of blue rather than my usual 2 but it still wasn't all that good.

The three galaxies of Arp 317 are said to be interacting. It is obvious that M 66 has been distorted by some interaction and has a large plume to the north and northwest. It is a very active galaxy with lots of star formation apparently triggered by the interaction. NGC 3638 has a tidal plume (that I failed to pick up due to insufficient exposure) I see little indication that M 65 is seriously distorted by any interaction. It looks pretty typical to the eye.

While redshift puts the trio about 50 million light-years away the accepted distance for them is about 35 million light-years. Not a surprising difference as the group is traveling through space together. This motion can add or subtract from the cosmological redshift distance enough to account for the difference. Redshift is sufficient to say the distance is 100 million or 200 million light-years but isn't accurate enough to work very well with our near neighbors like this group.

I notice a group of faint galaxies in the image at 1.63 billion light-years give or take a bit. The search radius of my field failed to turn up any group at that distance labeled in NED.

14" LX200R @ f/10, L=6x10' RG=2x10' B=4x10', STL-11000XM, Paramount ME