Lewis Swift discovered NGC 5624 = Sw. VI-66 on 9 May 1887 and recorded "eF; S; lE; Theta Bootis in field." His position is 12 seconds too far west. Howe measured an accurate micrometric position (MN, LXI, 1900).

400/500mm - 17.5" (7/12/99): faint, fairly small, elongated 3:2 N-S, 1.0'x0.7', weak concentration. The galaxy is collinear with two mag 12 stars 5.1' and 7.7' SSE. Located 20' SE of mag 4.0 Theta (23) Boo.

600/800mm - 24" (6/29/16): at 260x; moderately bright, elongated 4:3 N-S, , ~0.8'x0.6'. The surface brightness is irregular and the outline asymmetric; specifically the galaxy is brighter on the north end [appears to be an HII knot on the SDSS]. Arp 45 (pair) lies 1.1° WNW.

Notes by Steve Gottlieb