William Herschel discovered NGC 5144 = H IV-70 on 6 May 1791 (sweep 1005) and recorded "pB, R, almost equally bright throughout, resembling a very ill defined planetary nebula, about 0.5' diameter." Classified by Herschel in category IV (planetary nebula).

400/500mm - 18" (6/21/03): fairly faint, slightly elongated, fairly small, 0.8'x0.7'. Broad, weak concentration. Five or six mag 11.5-12 stars are in the field with the closest 1.9' N. Located 25' NW of mag 7.4 SAO 7817.

600/800mm - 24" (6/4/16): at 375x; moderately bright, irregularly round, fairly small, 0.7'x0.6', mottled or uneven surface brightness but no distinct core. Situated at the midpoint of a mag 11.8 star 1.9' NNW and a mag 13.7 2.0' SSW.

NGC 5144 apparently has a merged companion at the south edge, identified as NGC 5144 NED01 = LEDA 200298. It appeared as a quasi-stellar knot (less than 6" diameter) at the south edge of the halo, just 18" from the center of the main galaxy!

Notes by Steve Gottlieb