William Herschel discovered NGC 2639 = H I-204 = h518 on 9 Mar 1788 (sweep 815) and remarked "cB, vS, lE, milky." His position (Caroline Herschel's reduction) is 2' NW of UGC 4544. John Herschel observed the galaxy on 4 sweeps and it was logged 13 times at Birr Castle. On 12 Mar 1850, a "F appendage" was suspected and in 1863 a "F twist starting from sf end and turning p and np".

400/500mm - 17.5" (3/28/92): fairly bright, moderately large, elongated 2:1 NW-SE, 1.6'x0.9', halo gradually increases to a small brighter core. A mag 13 star is 2.5' SE. There are several fairly bright stars in the field including two mag 10.5 stars 4.6' E and 5.2' NE.

Notes by Steve Gottlieb