John Herschel discovered NGC 2842 = h3158 on 8 Mar 1836 and reported "F, vS, between two stars, in a field full of milky way stars. No doubt of the nature of the object." His position and description matches ESO 091-004.

600/800mm - 24" (4/11/08 - Magellan Observatory, Australia): fairly bright, moderately large, elongated 3:2 NW-SE, 1.2'x0.8', sharply concentrated with a small, very bright core. A mag 12 star is at the west edge of the halo and a mag 14 star is at the SE edge. Located 3.7' SSW of a mag 9.7 star. NGC 2887 lies 1.1° SE.

Notes by Steve Gottlieb