Harold Corwin

This is the 7th object in the very last list of new nebulae that Lewis Swift published, his "List No. 12 of Nebulae discovered at Lowe Observatory, Echo Mountain, California, for 1900.0". The list appeared in MN 59, 568, 1899, when Swift was 79 years old; it presents us with a list of 45 nebulae, all with poorly-determined positions, at least one demonstrably in error by 2 degrees in declination, with a couple of others more than a degree off in RA. One object (IC 5179 and its synonyms, which see) was found by Swift on three different occasions and received three IC numbers, and another (IC 5003 and its synonyms, which see) four.

So, I was not surprised to find the seventh object (found on the same night as one of the discoveries of IC 5179) missing from its nominal position on the sky. Taking the lead from IC 5183 (= IC 5179), the other object found on 20 Sept 1897, I am going to suggest that the declination is probably in error rather than the RA.

Before I get to my candidate objects, here is Swift's description, copied verbatim from the MN list: "eeF, R, S, lE, 8m * n, e dif[ficult]." The only clue he gives us that is really worth noting is the 8th magnitude star to the north. We will assume that this star was within the 33-arcmin field of Swift's preferred eyepiece.

If this is the case, then the best candidate is probably NGC 594 close to exactly three degrees south of Swift's position. The star is about 10 arcmin north, just a bit to the west, and the galaxy fits Swift's description.

Another candidate with a star about 12 arcmin to the northwest, is just three degrees north of Swift's position. This one, MCG -02-05-006, bears no NGC or IC number, and is somewhat fainter than the other viable candidates.

IC 141 is close to the same RA as Swift's -- as are NGC 594 and the MCG galaxy -- but its declination is about 1 degree, 13 arcmin south of Swift's nominal place, a less "desirable" difference than an even number of degrees. And the star is well out of Swift's field if the galaxy is assumed to be centered.

NGC 599 and NGC 601 are also possibilities, but they are a pair at about 12 arcmin with roughly the same RA and brightness -- if Swift saw one, why not the other? And their bright stars are southeast and southwest, not north.

Finally, the very faint object (at 01 32 53.2, -13 01 30) that I picked out many years ago in Scotland when I was young and naive is just too faint for Swift to have seen with his 16-inch refractor.

So, I am going to suggest that Swift re-discovered NGC 594 -- but I won't insist on it.

― IC Notes by Harold Corwin

Drawings, descriptions, and CCD photos are copyright Andrew Cooper unless otherwise noted, no usage without permission.

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