NGC/IC Project Restoration Effort

===== NGC 3931. WH's RA is 1 minute too large. This was first mentioned, as far as I can determine, by Anders Reiz in his thesis published in the Lund Annals, No. 9, in 1941. Reinmuth took a much fainter galaxy closer to WH's position as N3931. But even though it is a high-surface-brightness object, it is quite faint and very small. If WH could have seen it, I think he would have simply counted it as a star. Perhaps a visual investigation is in order, but this galaxy is so much fainter than the one just a minute of time preceding, that I think that Reiz must have chosen the correct object. Here is a curious footnote. Dreyer reports in his 1912 notes to WH's lists that Bigourdan could not find NGC 3931. However, looking at Bigourdan's big published table, we find a "Nova" as the very next object following his entry for NGC 3931. He found it the same night that he searched for N3931. Bigourdan did not include this new nebula in any of his lists of new objects, so it has no IC number. Reducing this observation, however, shows that it refers to the very object that Reiz picked up 40 years later. Finally, the number "NGC 3917A" is sometimes put on this object. This was first done by Philip Keenan in a 1935 paper (ApJ 82, 62); I've copied the number only to make it clear which galaxy Keenan actually listed. Let's not carry this any further, shall we?

===== NGC 3931 17.5" (3/19/88): fairly faint, small, round, bright core. Located 4.9' W of mag 8.6 SAO 28166. NGC 3917 lies 11' NNE.