Guillaume Bigourdan discovered IC 143 = B. 132, along with numerous other HII regions and star clouds in M33, on 28 Oct 1889.

400/500mm - 17.5" (10/25/97): appears as a very faint, hazy patch close WNW of a mag 13.5 star. This HII region (M31-A75) is located 5' W of NGC 604 and 8' NNE of the center of M33. M33-A71 is another very faint, 20" knot just 1.3' NW that appeared slightly brighter than IC 143. This is the second of three HII regions along with IC 142 3.5' WSW and NGC 604 5' E in the spiral arm attached at the west side of M33 and winding towards the NE.

Notes by Steve Gottlieb