Heinrich d'Arrest discovered NGC 4089, along with NGC 4901, on 2 May 1864 and described a double nebula separated by 3 sec in RA. His mean position from 3 nights matches CGCG 128-020 = PGC 38298.

400/500mm - 17.5" (5/14/88): faint, very small, slightly elongated, bright core, faint stellar nucleus. Forms a very close pair with NGC 4091 37" E of center. First of six in field within the NGC 4065 cluster.

Notes by Steve Gottlieb