When I'm now analyzing my galaxy observations from the past weekend, I found to my joy that I had observed a member to the galaxy cluster Abell 1738 in Ursa Major. It is situated 2º.7 N of Mizar in the Big Dipper. I had seen the galaxy MCG+10-19-68 (=PGC46931) in the centre of Abell 1738. I saw the cluster symbol on my chart but I was not sure if the galaxy belonged to the cluster. NED verified the membership and gives the magnitude as 16.58 (B-mag?) but APASS gives the visual magnitude as V=15.64. MegaStar gives the size as 0'.5x0'.4 but NED says 0'.2x0'.13. I wrote during my observation with my 12-inch Dob and 214x magnification that PGC46931 was "very faint, pretty small and had a low surface brightness". The galaxy's redshift is z=0.1154 and radial velocity +34599 km/s. NED gives the distance as 476 Mpc, 1.55 billion light-years. It is the most remote galaxy I have ever seen, more distant than even the galaxies in the famous Abell 2065 in Corona Borealis! I could not see the neighbour MCG+10-19-69. I have so far seen 20 Abell galaxy clusters. During the last two weeks, I had observed 146 new galaxies with the 12-inch and I had never seen so many new galaxies during a new moon period! I had also logged my 111th galaxy in the Coma cluster, Abell 1656. That was the last chance of darkness before our bright summer nights here at latitude 60º N.
Edited by timokarhula, 25 April 2018 - 05:35 AM.