Heinrich d'Arrest discovered NGC 4031 on 6 Apr 1864 with the 11-inch refractor at Copenhagen. His single position is an exact match with CGCG 157-082 = PGC 37855. He mentioned the mag 15.5 star at the south end, though his magnitude estimate (17th) is too faint.

400/500mm - 17.5" (2/24/90): very faint, fairly small, elongated SSW-NNE. A mag 15.5 star is at the SW end and a second mag 15 star is 0.7' N of center.

Notes by Steve Gottlieb