William Herschel discovered NGC 3732 = H II-552 = h913 on 4 Mar 1786 (sweep 597) and noted "F, pS, iR. Following a very small star." His position is accurate. JH recorded (sweep 129) "S; R; psbM; has a * 14m, 45° sp."

Andrew Ainslie Common found it in 1880 with his 36-inch and included it as #20 in his Copernicus discovery list: "F, R, a cluster of 3 similar ones 15' N." The "3 similar ones" might refer to MCG -01-30-005 = NGC 3722, MCG -01-30-007 = NGC 3724 and MCG -01-30-008. Unfortunately, there are a number of faint galaxies in in this area so these identifications are uncertain.

400/500mm - 17.5" (4/5/97): moderately bright, fairly small, elongated 4:3 ~E-W, broad concentration with a bright core. A mag 12 star lies 1.0' SW. A group of at least six very faint galaxies lies between 10'-20' N and NGC 3723 lies 26' WSW.

17.5" (5/2/92): fairly faint, fairly small, slightly elongated but irregular outline, fairly bright elongated core. A faint stellar nucleus is visible at moments. A mag 13 star lies 1.0' SW. Located 35' W of Theta Crateris (V = 4.7).

Notes by Steve Gottlieb