Albert Marth discovered NGC 139 = m 10 (along with NGC 138 and NGC 141) on 29 Aug 1864 with Lassell's 48" on Malta and logged "eF, S." Marth's position is 2' N of CGCG 409-022 = PGC 1900.
400/500mm - 17.5" (10/8/88): very faint, small, almost round. Located in a group with NGC 138 5' NNW.
Notes by Steve Gottlieb