Harold Corwin

There is a 10 minute of time digit error in Swift's RA -- it is too large. The galaxy, ESO 345-G017, matches his description "vF, pS, R" pretty well. It is also the only galaxy in the area that he could have seen.

Another double galaxy sometimes mistaken as IC 5239, ESO 345-IG038, while closer to the nominal position, is much too faint to have been seen by Swift. Its combined R magnitude is only 16.0, while that for ESO 345-G017 is 13.4, well within range of Swift's 16-inch on Echo Mountain.

So I wrote not long ago when I was reviewing my earlier work on the IC. In the meantime, Steve Gottlieb did some observing in the area and had this to say in an email in September 2018:

I was able to take a look a few of Swift's questionable IC objects at the star party using my 24", including IC 5239. As you commented in your summary, there is nothing near Swift's position that he might have seen (ESO 345-IG 038 is much too faint) and assuming a 10 minute time error (too large) then ESO 345-017 is a reasonable candidate. I logged this galaxy as "extremely faint, small, round, 18" diameter (core only seen), required averted vision."

Interestingly, just 18' further E and 1.3' south is ESO 345-021, which was somewhat more obvious in the eyepiece (about 1/2 magnitude brighter). I called it "very faint, small, roundish, 20"-24" diameter." ESO 345-021 is 8 minutes of RA west of Swift's position and a very good match in declination. So, I'd suggest ESO 345-021 is also a reasonable candidate for IC 5239.

Following Steve's observations, I've adopted ESO 345-G021 as the most likely candidate for Swift's object, but retain ESO 345-G017 as a possibility.

― IC Notes by Harold Corwin

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