John Herschel discovered NGC 642 = h2431 (along with NGC 639 = h2430) on 27 Sep 1834 and recorded "F, S, R, gbM, 15", has a star near it, following.". His mean from 3 observations matches ESO 413-014 = PGC 6112.

400/500mm - 17.5" (12/20/95): brighter of a pair with NGC 639 1.7' SW. Faint, fairly small, elongated 3:2 ~N-S, ~1.2'x0.8' (fades into background so difficult to estimate PA and size), broad weak concentration. A mag 13 star is just off the SE end 50" from center.

Notes by Steve Gottlieb