R.J. Mitchell and George Johnstone Stoney, LdR's assistants, discovered NGC 5723 and 5721 on 16 Apr 1855 while observing the NGC 5714 group. A sketch shows a small quartet to the northeast of NGC 5717 and NGC 5723 matches MCG +08-27-015 = PGC 52354, though the last object (NGC 5724) is a single star.

The RNGC entry for NGC 5723 applies to NGC 5721. The MCG entry for NGC 5723 is possibly correct (the coordinates are imprecise) though it may erroneously refer to PGC 2286446, which lies northeast of the quartet. CGCG errs in calling the close pair NGC 5721 + NGC 5723 instead of NGC 5721 + NGC 5722.

400/500mm - 17.5" (6/27/98): this galaxy is the last of five viewed in the NGC 5721 group and part of small quartet (3 seen). Like NGC 5721, this marginal object required concentration and averted vision to momentarily glimpse a 16th magnitude stellar object (only core viewed) 1.5' NNE of NGC 5722. 17th magnitude NGC 5724 just 43" NE was not visible.

Notes by Steve Gottlieb