Lewis Swift discovered IC 2531 = Sw. XI-104 on 15 Feb 1898 and logged "eeeF; pS; cE; trapezium n and nf; D * np." His position is poor, but the identification is certain.

400/500mm - 17.5" (2/1/03): large, low surface brightness streak, 1.5'x0.3', oriented WSW-ENE; broad, weak concentration. In a field with a number of mag 10-11 stars. Located 6' SE of a wide mag 10.7/13.5 pair and a similar distance south of a quartet of mag 11/12 stars. At the southwest edge of the 220x field are a trio of mag 9-10 stars.

Notes by Steve Gottlieb