Harold Corwin

IC 4863 is a double star about 50 seconds of time west of Swift's original position. The position in the IC is from Howe (MNRAS 58, 515, 1898) who found a much fainter double about 20 seconds west of Swift's position. We can be reasonably sure about the identifications as Swift's description and note (in MNRAS 57, 628, 1897 and PASP 9, 186, 1897) are quite effusive: "B, eS, lE, stellar; looks like a close D * both nebulous." His appended note, in full, reads:

This is also a singular object. I have never seen but one resembling it, and that was on the same night, which I think is N.G.C. 6861. It resembles a close, bright, double star, each component having a small, bright, round, star-like, nebulous disk. A power of 200 failed to divide it.

Also, there may be some fainter stars near the double. These might enhance a nebulous appearance of the brighter two on nights of less than perfect seeing. Swift, too, was scanning within 20 degrees of his southern horizon, which would not help to clarify his view of the object.

Howe's double is composed of two 15th magnitude stars having a position angle of about 100 degrees. Though he does not mention the magnitude, he does give the position angle, and his note about the object being 20 seconds preceding Swift's position clearly identifies it. The object is much too faint for Swift to have called it "B".

― IC Notes by Harold Corwin

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

A complete list of credits and sources can be found on the about page