Albert Marth discovered NGC 5159 = m 258 on 30 Apr 1864 and noted "eF, S, lE."

400/500mm - 18" (5/29/05): extremely faint, fairly small, elongated ~2:1 NNW-SSE. Not noticed initially but then caught the slightly brighter core. When drifting across the field very faint, low surface brightness extensions could be glimpsed increasing the size to nearly 1.0'x0.4'. Located 47' NE of NGC 5148, another dim galaxy.

Notes by Steve Gottlieb