Harold Corwin

IC 611 is almost certainly identical with IC 610. Almost.

Found the 20th of April in 1889 by Lewis Swift while he was still working in Rochester, his description of IC 610 is entirely appropriate: "eeF, pS, cE; in center of semicircle of 3 wide D sts". This is a fine description of the Scd: spindle near Swift's position (10 23 32, +20 29.2 for B1950.0).

Two nights later, he found an object just 10 seconds of time east, and one arcminute north, of his position for IC 610 -- closer in fact to the galaxy than his position for IC 610. His description, however, is considerably sparcer: "eF, S, lE". The "lE" is bothersome, as is the fact that Swift himself found the galaxy just two nights on. Did he have any memory of the fields in which he found new nebulae?

So, in spite of the position, the identity is not quite a "slam-dunk". What else in the area might he have seen? Not much actually -- there is nothing worth noting either a degree north or south of the galaxy, nor is there anything 1 or 2 minutes of time east or west. There are three other objects at more or less random positions nearby worth noting -- but all have strikes against their being IC 611:

The double star at 10 23 27.8, +20 30 42 is just an arcminute south of a 10th magnitude star that Swift would surely have noted. The galaxy 2MASX J10245618+2024102 at 10 22 12.2, +20 39 25 is quite faint and nowhere near Swift's nominal position. The same is true of the galaxy WAS 11 at 10 24 42.1, +20 42 11. This one at least has a higher surface brightness.

In the end, however, it is easiest to simply equate the two numbers. Is it right? Well, probably. I'd sure like to see Swift's original log books, assuming they still exist, of course.

― 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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