John Herschel discovered NGC 5011 = h3473 on 3 Jun 1834 and recorded "pB; pS; R; gbM; 15"; in a curve of 3 or 4 stars." His mean position (3 nights) is accurate. Joseph Turner recorded "suddenly much brighter in the middle, about 25" in diameter", using the 48" GMT on 1 May 1878. (p.173 in logbook)

300/350mm - 13.1" (2/19/04 - Costa Rica): fairly bright, fairly large, oval 4:3 NNW-SSE. Moderate even concentration to a brighter core and a faint stellar nucleus. NGC 5026 lies 17' NE. Located 12' WNW of mag 6.2 HD 114873 and 23' NE of mag 5.2 HD 114474.

400/500mm - 17.5" (2/28/87): fairly faint, small, round, weak concentration. The following three brighter stars are equidistant to the E; mag 9.1 SAO 223985 7.4' NE and two mag 11 stars 7.8' ESE and 7.3' SE. Located 12' WNW of mag 6.2 SAO 223989. Outlying member of the Centaurus cluster or in a group surrounding the Centaurus cluster (AGC 3526).

Notes by Steve Gottlieb