DeLisle Stewart discovered IC 4839 = DS 575 on a plate taken at Harvard's Arequipa station on 16 Sep 1901. He reported "F, S, * inv in neb."

600/800mm - 25" (10/16/17 - OzSky): at 244x; moderately bright, fairly large, elongated 5:3 NW-SE, broad mild concentration, elongated core region appears to be a bar [confirmed later on the DSS]. At 397x, the outer halo was slightly irregular in brightness, suggesting some spiral arcs. Forms an attractive pair with IC 4837 3.5' SW. ESO 184-042 lies 11' WNW. Member of the Pavo-Indus Supercluster.

Notes by Steve Gottlieb