R.J. Mitchell discovered NGC 5805 on 3 Apr 1854 while observing the field of NGC 5794/5797/5804 with LdR's 72". He noted "I think there is a vF, S neb at Delta [in sketch], about 2' +/- from Gamma [NGC 5804]." The observation was confirmed the following year. The diagram is a perfect match with MCG +08-27-039 = PGC 53435. This is an overlapping double system.

The RNGC misidentifies KUG 1454+498 = PGC 53381 as NGC 5805. Unfortunately, NGC 2000, Deep Sky Field Guide and the first edition of the Uranometria 2000.0 Atlas repeat the RNGC error. NGC 5805 is referred to in the UGC notes to[NGC 5804 but is not identified as NGC 5805. Malcolm Thomson mentions this error in his unpublished Catalogue Corrections as well as in Harold Corwin's NGC identification notes.

400/500mm - 17.5" (6/21/93): extremely faint, very small, round, just visible continuously with averted. Located on line between a mag 14 star 1.4' SSE and NGC 5804 2.6' NNW. Last of four in a group.

Notes by Steve Gottlieb