Hermann Kobold discovered IC 3998 = K. 2-20 on 22 Apr 1895 with the 18-inch refractor at Strasbourg and recorded "eF, pS."

300/350mm - 13.1" (4/29/84): extremely faint, very small, between NGC 4874 and NGC 4889 in core of AGC 1656.

400/500mm - 17.5" (4/21/90): located in the central core of AGC 1656 between NGC 4874 and NGC 4889. Extremely faint and small, round. Forms a close pair with PGC 44652 = Goodwin #458 1.1' SSE. Located 2.6' ENE of NGC 4874 and a swarm of galaxies are in the field surrounding NGC 4874. Also located 4.7' due west of NGC 4889 (brightest in AGC 1656).

Notes by Steve Gottlieb