Harold Corwin

IC 4257 is one of 7 nebulae near M 51 found by Keeler on two Lick 36-inch reflector plates. The other six are all in their measured places, but there is no trace of IC 4257 where Keeler placed it. The original position, published in a short Monthly Notices paper, is not significantly different from a refined position that appears in the Lick Publications, Volume 8, a few years later.

About 4 arcmin north of the published position, however, is a faint galaxy that pretty well matches Keeler's description. However, the position is not exactly 4 arcmin north, even taking into account systematic offsets (from modern positions) of +0.3 sec and +4 arcsec in Keeler's positions for the other six galaxies. This makes a simple typo unlikely, suggesting some sort of mistake in measurement or reduction on Keeler's part. However, Keeler claims to have seen the object on two plates, so one would think that a mistake working on one would be found by comparison with the other.

Whatever happened, we cannot now be sure which galaxy Keeler measured. I've
also listed a nearby star that could -- really stretching here -- be Keeler's
object.

― 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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