Harold Corwin

IC 3986. This is a galaxy from among those that Swift found during his last year of observing at Echo Mountain in Southern California. The position puts it just a minute of time west of ESO 443-G032, so I have assumed a one minute error in Swift's RA.

However, in April 2016 Steve Gottlieb suggested that Swift's object might be ESO 443-G024. Swift's position is actually further off this galaxy -- 52 seconds in RA and 7.8 arcminutes in Dec -- but it better matches his description, "eeF, pS, R; 10m * nr nf" -- if the star is actually northwest, rather than northeast.

This may seem more of a stretch, but Steve has pointed out that G024 is brighter (V = 12.1 vs. 12.4, from the ESO-LV photometry) and larger (D_25 = 2.2 arcmin vs. 1.8 arcmin, also from ESO-LV), and is therefore more likely to be picked up than G032. This is exactly his experience in at least two observations of the field in 1993 and 2016.

One curiosity: There are actually two stars north and west of the galaxy. The nearer one that I label "nw" has V_Tycho = 11.65, while the slightly more distant one labeled "wnw" has V_Tycho = 11.11. If this is the correct galaxy, which star did Swift mean? We, of course, have no answer to that.

So, I am going to accept Steve's suggestion that ESO 443-G024 is actually Swift's object. This is obviously still uncertain, so I've put colons on the number. But I feel confident enough about it to downgrade ESO 443-G032 with question marks.

― IC Notes by Harold Corwin

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