Harold Corwin

IC 685. Swift's note "New General Catalogue 3605, 7, 8 in field" should have given this away to anyone with access to Swift's original paper. Well, I didn't notice this, but Malcolm Thomson did. Gary Kronk reported Malcolm's note to me in May 2017, and I'm pleased to acknowledge their work in setting the record straight.

The galaxy usually taken as IC 685 is PGC 34871. It is reasonably close to Swift's published position and more or less matches his description "eeF, pS, R; * nr nf." It even has the "* nr nf" (there are in fact two there). However, the galaxy is very faint (even by modern standards), probably beyond Swift's reach even with his 16-inch. And the NGC galaxies are five minutes of time to the west.

I suspect that the five minute error is what caught Malcolm's eye. Given that, the galaxy that Swift saw is almost certainly UGC 6296 = PGC 34419. It is well within his optical grasp, is just about 15 arcminutes south of the NGC objects at the correct declination, and has a single star 1.3 arcminutes northeast. The only element of Swift's description that does not match is the note "R" -- the galaxy is considerably elongated at about PA = 168 degrees.

Nevertheless, with the five minute error corrected, the galaxy fits Swift's position to within his usual errors, so there is little doubt that Malcolm is correct with his identification.

― IC Notes by Harold Corwin

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