Lewis Swift discovered IC 5139 = Sw. XII-28 on 18 Aug 1897 and noted "vF, S, lE." His RA is 16 seconds too large, actually a fairly close match considering his very poor positions during his last summer of observing.

400/500mm - 17.5" (8/6/97): fairly faint, fairly small, elongated 5:2 SW-NE, 1.2'x0.5', weakly concentrated. A faint star appears is attached at the NE end (just visible on DSS).

17.5" (7/25/95): fairly faint, fairly small, elongated 5:2 SW-NE, 1.2'x0.5', fairly high surface brightness, broad concentration to a brighter core. There appears to be an extremely faint star or knot at the NE end. Bracketed by two mag 14.5 stars 2' NE and two similar stars 2' SW.

Notes by Steve Gottlieb