NGC/IC Project Restoration Effort

===== NGC 1980. This very faint nebula around iota Orionis has been the subject of some controversy recently (Steve Gottlieb brought this to my attention late in October of 2014). WH first suggested its existence early in 1786 (Sweeps 517 on 31 January, and 529 on 24 February). Could WH have really seen it, or is his "nebulosity" simply the result of the overlapping coronae of the several bright stars in the area, not least that of iota itself? Here are WH's notes: Sweep 517: "Iota Orionis seems with its neighbouring stars to be involved in milky nebulosity, but it is so faint and the number of stars makes the field so bright, that I cannot assure myself; though I compared this spot with the preceding and foloowing ones." Just four minutes before this observation began, WH noted "Very clear" in the sweep. Sweep 529: "Iota, certainly affected; but no more than what the tinge of the bottom in this neighbourhood will account for." Again, just seven minutes this time, WH noted "Clear and dark" in the sweep. Wolfgang, after a long study of WH's observations of nebulae, believes that WH's suggestions of nebulosity are visual illusions brought about by the stars in the area. He points out, correctly, that "The southern part of M 42 has a very low surface brightness." I'm inclined to agree, but don't want to dismiss the observations entirely. For the record, JH recorded only "i Orionis involved in a feeble neb 3' diam" on 8 January 1831; and Bigourdan says "Not seen" on 27 December 1886, and "I cannot see nebulosity around this bright star, which is BD -6 1241," on 15 January 1896. So, given the uncertainty, I am keeping the number "NGC 1980" as a possibility for future observers to confirm or refute as they please. Its position is certainly not a problem: WH is clear that it surrounds iota Orionis. Only the visibility of the faint nebulosity here, the southern reaches of M 42, is in question.

===== NGC 1980 13.1" (1/28/84): very faint, large nebulosity of low surface brightness surrounding Iota Orionis (V = 2.8). Very difficult to distinguish from glare of Iota. M42 lies 30' N.