William Herschel discovered NGC 3893 = H II-738 = h982 on 9 Mar 1788 (sweep 816) and recorded "pB, pL, R, mbM." His position is accurate. JH logged "B; pL; R; gb and psmbM; 60"."

Bindon Stoney, observing on 15 Apr 1852 with LdR's 72", logged "Spiral probably, knot in south edge and a * outside preceding edge." The next night he also noted the "spiral branch seems to start from the south edge and go round the following and n sides as far as the preceding star." Further observations of the spiral structure were made in 1857 and 1861.

400/500mm - 17.5" (4/7/89): fairly bright, moderately large, oval 3:2 NNW-SSE, 2.4'x1.6', broad moderate concentration, small bright core. There is a hint of spiral structure with an impression of an arm attached at the SW end trailing to the east. A mag 13.5 star is involved at the NW side 1.0' from the center and a mag 10.5 star is 3.1' SW. Forms a pair with NGC 3896 3.7' SE. NGC 3893 is a member of the NGC 3877 subgroup of the NGC 3992 (M109) group = LGG 258.

900/1200mm - 48" (5/9/18): I was quite impressed with this gorgeous asymmetric spiral. At 488x and 610x it appeared very bright, very large, oval 3:2 NNW-SSE, slightly over 3'x2'. The slightly elongated core contains a bright, circular nucleus that rises to a very bright non-stellar peak. A prominent spiral arm is rooted at the southwest side of the core. It emerges to the south with a 15th mag star superimposed, and unfurls fairly sharply clockwise to the southeast as it separates from the core. The arm shoots nearly straight north on the east end of the halo, ending nearly 1.5' NNE of center. The arm is relatively thin and has a high contrast with the much darker interarm gap to the west. An easy HII knot is within the arm, 50" ESE of center, and a second bright knot with a stellar center is just 15" S. The northern section of the arm is mottled but I didn't notice any specific knots. A second thin arm is attached on the east or northeast side of the core. It curls around the north side of the core to the west and ends at a mag 13.4 star [0.9' NW of center]. This arm has a sharply defined, hard outer edge at 610x. Forms a pair (similar redshift) with NGC 3896 3.7' SE.

MCG +08-22-009 was also picked up in the field 5' NE. It appeared bright (V = 14.6), fairly small, elongated 3:2 SSW-NNE, 20"x14", fairly high surface brightness. It contains a very small, very bright nucleus.

Notes by Steve Gottlieb