NGC/IC Project Restoration Effort

===== NGC 3560 = NGC 3559. During his MicroSky work, Glen Deen could not find NGC 3560. There is indeed nothing in its position, copied exactly from the GC by Dreyer, and before that from JH's 1833 catalogue. Checking that catalogue, though, I found that JH himself equates his 834th object with his father's III 79. The descriptions are similar, and Sir John himself says, "The PD of the working list is 6 arcmin out, owing to which I have often before looked for it in vain." So, he must have had the correct polar distance in front of him when he wrote this. But his NPD is exactly 50 arcmin out. I suspect that the 1833 NPD suffers from a typographical error: in place of "77 53 50," read "77 03 50." D'Arrest also noticed the 6 arcmin problem (he also marks the name III 79 with a question mark, and does not mention JH's number), and has two observations of this to Sir John's one. Thus, it is d'Arrest's presumably more accurate position that Dreyer adopted for NGC 3559. However, Dreyer had only JH's position for h834 to use. This is exactly 50 arcmin in declination out from d'Arrest's correct position for III 79. Since Sir John had included h834 in GC as a separate object, Dreyer followed JH's precedent. So, we are left with two numbers for the same object. Curiously, though, neither Dreyer nor JH have any note in GC or NGC about the identity, which JH himself had noted over 30 years earlier.

===== NGC 3560 See observing notes for NGC 3559.