Édouard Stephan discovered NGC 3570 = St IX-23, along with NGC 3574, on 15 Mar 1877. His position matches UGC 6240. This galaxy is the brightest in a group with NGC 3754 2.9' NE.

Emmanuel Esmiol, in a re-reduction of Stephan's positions at Marseille Observatory, removed NGC 3570 and replaced it with an anonymous galaxy, as if the NGC position is in error, but his new position matches the old!

400/500mm - 17.5" (4/14/01): fairly faint, small, round, 30" diameter. Forms a pair with NGC 3574 at 2.9' NE. Brightest in a faint group.

Notes by Steve Gottlieb