Lewis Swift discovered IC 1858 = Sw. XI-45, along with IC 1859 and 1860, on 5 Sep 1897. He reported "vF; pS; R; 1st of 3." His RA is 25 seconds too small and IC 1859 is actually a bit further west. The position was corrected in Robert Baker's 1933 "Catalogue of 985 Extragalactic Nebulae in a Region in Fornax and Eridanus", based on photographs taken with the Bruce astrograph in South Africa.

400/500mm - 17.5" (12/9/01): extremely faint, small, slightly elongated N-S, 25"x20" (viewed core only). Faintest in a trio with IC 1859 and IC 1860 in the ACO S301 cluster. Located 8' SW of IC 1860 and 7' S of IC 1859.

600/800mm - 24" (11/23/19): at 375x; between faint and fairly faint, elongated 5:2 N-S, 0.75'x0.3', slightly brighter core, low uneven surface brightness. One of the brightest members of cluster ACO S301. IC 1860 lies 8' NE.

24" (12/6/18): at 260x; between faint and fairly faint, very elongated 3:1 N-S, ~0.9'x0.3', brighter core. Second brightest member of the galaxy cluster ACO S301.

Notes by Steve Gottlieb