Heinrich d'Arrest discovered NGC 3764 on 20 Apr 1862, in the field of NGC 3768. His position, from two observations, matches CGCG 097-025 = PGC 35930 and he mentions a mag 15 star that follows by 14.9 seconds of RA.

NGC 3764 was probably discovered earlier by R.J. Mitchell at Birr Castle on 22 Mar 1857. While observing h923 = NGC 3768 he noted "npp is another of the same character, but fainter." Dreyer, while preparing the 1880 publication added the note "= GC 2466, nova d'Arrest", though only d'Arrest is credited in the NGC.

400/500mm - 17.5" (4/14/01): faint, small, round, 0.7' diameter, very small brighter core with direct vision. This is a close interacting system (unresolved). Forms a pair with NGC 3768 5.5' SE. Both William and John Herschel missed this galaxy although they observed nearby NGC 3768.

Notes by Steve Gottlieb