Harold Corwin

IC 5011 = IC 5013. These two IC entries, both found by Swift in the summer of 1897 (but on different nights: 25 July and 29 August, respectively) from Echo Mountain, are the 193rd and 194th objects in his big 11th list of new nebulae in AN. There is, however, nothing in the position for IC 5011.

Because the descriptions are similar -- "pB, vS, eE" for I5011 and "eeS, eE in meridian; curious object" for IC 5013 -- I am pretty sure that Swift dug out the same galaxy. In that case, IC 5011 has a 1 minute 18 second of time error in its RA, while I5013 is only 8 seconds off. Both declinations are within an arcminute of reality. Swift does not say what makes I5013 a "curious object", and that phrase does not occur in any of the three papers where Swift published his third Echo Mountain list (where these two are the 15th and 16th entries).

The galaxy's PA is around 5 degrees, and it is seen by us as nearly edgewise, so matches Swift's descriptions. Two of the companions are quite faint so would not have been seen by Swift, but the third to the southeast is bright enough that it might have been visible under good conditions. Perhaps this is the "curious" aspect of Swift's observation.

― IC Notes by Harold Corwin

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