Albert Marth discovered NGC 509 = m 47 on 1 Oct 1864 with Lassell's 48" on Malta and logged "vF, S, E." His position is accurate.

300/350mm - 13.1" (8/24/84): very faint, small, slightly elongated ~E-W. Two faint stars are north and south.

400/500mm - 17.5" (10/17/87): faint, small, elongated ~E-W. Located between a mag 14 star 1.9' SW and a mag 13.5 star 1.4' N. Forms a pair with NGC 505 7' WNW in the NGC 524 group.

Notes by Steve Gottlieb