NGC/IC Project Restoration Effort

===== NGC 4882 = NGC 4886. These two NGC numbers are both credited to d'A, so at first glance, it seems a bit strange to equate them. But looking into his big monograph, we see that he has just a single observation for N4882 on a different night (22 April 1865) than the two nights (6 April and 5 May 1864) on which he observed N4886. Furthermore, the RA offset (seven seconds of time west) is the same as for another discovery of his on the same troubled night, NGC 4884, which is identical to NGC 4889. Here are the observations that yeilded these two numbers: NGC RA (J2000) Dec DelRA DelDec Notes (modern - d'A) seconds arcmin 4864 12 59 11 +27 58.8 +2.3 -0.2 4865 12 59 15 +28 05.1 +4.9 0 4869 12 59 22 +27 54.7 +1.4 0 4874 12 59 33 +27 58.0 +2.7 -0.4 4881 12 59 57 +28 15.0 +0.8 -0.2 4882 12 59 58 +27 58.7 +6.5 +0.6 = N4886 4884 13 00 01 +27 58.4 +7.1 +0.2 = N4889 4895 13 00 14 +28 12.0 +3.9 +0.1 Mean +3.70 +0.01 Std Dev +-2.17 +-0.28 Mean +2.70 -0.12 "4882" and "4884" omitted Std Dev +-1.40 +-0.17 It's easy to see, even on this night with a relatively large systematic RA offset in d'A's observations in Coma, that the measurements leading to NGC 4882 and NGC 4884 are well east and south, not just of the modern positions, but of the other measurements. Others may wish to look into the reasons for this, but for now, it is enough to simply show that the two observations are anomalous. Other than the RA offset, d'A's observation would appear to fit NGC 4886 very well. He says, freely translated from his Latin, "Very faint, very small. Others, too many to count, near." (For a thoroughly idiosyncratic translation from Google Translate, try typing in d'A's original Latin: "Pertenuis et minuta. Numerosus nebularum exercitus sub adspectum venit: singulas omnes enumerare impossibile.") Sitting in the middle of the Coma Cluster, this is an accurate assessment. See NGC 4872 for a general discussion of d'A's observations in the Coma Cluster core.

===== NGC 4882 See observing notes for NGC 4886.