Édouard Stephan discovered NGC 593 = St XII-17 on 2 Nov 1882 with the 31" reflector at the Marseille Observatory and described a "vS group of stars, little elongated SSW-NNE, contains very slight nebulosity". His position is accurate though Stephan description of a cluster is of course incorrect.

400/500mm - 17.5" (9/26/92): extremely faint, small, very elongated 3:1 ~N-S, low surface brightness. In a small group with NGC 589 12' NE and NGC 601 3.3' ESE (see observation of 10/4/97). Incorrectly described as a nebulous cluster by Stephan.

Notes by Steve Gottlieb