John Herschel discovered NGC 4645 = h3412 on 8 Jun 1834 and recorded "pB; S; psbM; 12".". His position is ~2' west of ESO 322-066, the only nearby galaxy.

Pietro Baracchi observed the galaxy on 8 and 9 Apr 1885 and logged a new nebula that preceded by 38 seconds and 40" to the south, but at this offset is a faint double star.

400/500mm - 17.5" (4/7/89): fairly faint, fairly small, slightly elongated, sharp concentration. Member of the Centaurus cluster (AGC 3526).

Notes by Steve Gottlieb