NGC/IC Project Restoration Effort

===== NGC 4368 is probably NGC 4325. Dreyer notes that WH's "... RA is possibly 1 min too great (see under II 64 [= N4352]). Not found by Bigourdan." The note for N4352 reads, "RA is 1 min too great. The same is the case with several other nebulae observed this night (Sw 174, March 15, 1784) ..." The actual differences between WH's RA's and the true RA's varies from about 40 sec to well over a minute for the seven objects mentioned by Dreyer (N3810, N4067, N4294, N4313, N4352, N4371, and N4429). If N4368 is indeed N4325 (discovered by d'A), its difference is 1 min 28 sec, not an unreasonable value considering the other errors. The declination is 1.5 arcmin different, well within WH's usual observing errors. I can only speculate about the source of WH's error, since it does not affect every object observed in Sweep 174. Thus, it could be a correction due to a mistimed comparison star -- but different affected objects have different comparison stars. Or it could be that WH forgot to make the correction to the center of the field for the objects -- but since his field was only 15 arcmin across, the largest correction could only be half that value, or a bit less than 30 seconds of time at a declination of +10 deg. Also, this is a necessary correction for every object which does not sweep across the field center -- which is almost every object observed. I can't see WH forgetting such an obvious correction for a few objects in a sweep, but not for most others. Whatever caused the errors, the fact that they exist is clear, and N4368 seems to be affected. Finally, there is also the faint possibility that N4368 is N4320 (also found by d'A). However, that is fainter and smaller than N4325, and WH's Dec would be off by 3.0 arcmin rather than the 1.5 arcmin to N4325. The RA would also be further off, too, 1 min 40 sec, so overall, I do not think this is a strong possibility.

===== NGC 4368 See observing notes for NGC 4325.