William Herschel discovered NGC 3377 = H II-99 = h754 on 8 Apr 1784 (sweep 187) and noted "pB, S, r." John Herschel made three observations and called it "first Class". Auwers and d'Arrest also measured precise positions.

200/250mm - 8" (3/28/81): fairly bright, slightly elongated SW-NE.

300/350mm - 13.1" (2/25/84): bright, elongated 2:1 SW-NE, well concentrated to a small bright nucleus. Member of the Leo I Group (also called the M96 Group).

Notes by Steve Gottlieb