John Herschel discovered NGC 2397 = h3085 on 21 Feb 1835 and recorded "B, L, mE, gbM, 2' long, 1' broad." On a second sweep he called it "F, pL, pmE, pslbM, 90", pos of extension = 117°." His position and description matches ESO 58-30 = PGC 20766.

Joseph Turner sketched it on 15 Jan 1877 with the Great Melbourne Telescope as a thin streak oriented NW-SE and slightly brighter in the center (unpublished plate V, figure 41).

600/800mm - 24" (4/4/08 - Magellan Observatory, Australia): at 260x appears very bright, large, elongated nearly 5:2 NW-SE, ~2.4'x1.0', broadly concentrated to a brighter core and then rising quickly to a tiny brighter nucleus. A mag 14.5 star is just off the east end 1' from the center. Forms a pair with NGC 2397A 7' S. The companion was very faint, moderately large, very diffuse, elongated 4:3 ~N-S, ~1.2'x0.9'. NGC 2397 is part of the NGC 2442 group and situated 1.4° NW of NGC 2442.

Notes by Steve Gottlieb