William Herschel discovered NGC 2986 = H II-311 on 10 Mar 1785 (sweep 382) and logged "F, pL, mbM. I partly suspect a very small, faint one preceding it about a minute or two, but it may be only a few close very small stars." The comment about a "faint one preceding it about a minute or two" appears to refer to ESO 566-004 (Steinicke concurs), which was also picked up in my 17.5". WH observed NGC 2986 again during sweeps 542 ("cB; S; mbM; irr R") and 660, but did not mention the companion, so it did not receive a H-designation of NGC number. Engelhardt measured an accurate micrometric position.

400/500mm - 17.5" (2/28/87): bright, small, round, bright core, faint halo. A mag 14 star is 2.0' WSW. Forms a pair with ESO 566-004 2.3' WSW (just preceding the mag 14 star). The companion appeared very faint, small, diffuse.

Notes by Steve Gottlieb