William Herschel discovered NGC 2778 = H II-564 = h566 on 28 Mar 1786 (sweep 549) and noted "pB, S, R, mbM." His position was 6 sec of RA west of UGC 4840, within his usual margin of error. John Herschel logged 4 observations and estimated the size as between 20"-30". Brightest in a group.

400/500mm - 17.5" (3/28/92): fairly faint, small, irregularly round, very small bright core, stellar nucleus with direct vision. Forms a close pair with NGC 2779 1.7' NNE with NGC 2780 in the field 7.3' SSE. An evenly matched pair of mag 10 stars (at 38" in PA ~90°) is located 5' NNE.

Notes by Steve Gottlieb