John Herschel discovered NGC 3257 = h3255 on 2 May 1834 and recorded "vF; vS; R; sbM; 10". The preceding of a group [with NGC 3258 and 3260]." His mean position (3 observations) matches ESO 375-036.

400/500mm - 18" (3/17/07): faint, fairly small, round, 0.4' diameter, weak concentration with no definite core. Faintest of trio with NGC 3258 3.4' NNE and NGC 3260 5.4' NE in the Antlia Cluster (ACO S636).

Notes by Steve Gottlieb