Albert Marth discovered NGC 6490 = m 355 = St II-18 on 11 May 1864 and noted "vF, vS, stellar." His position is within 1' of UGC 11033. Édouard Stephan rediscovered both galaxies in July 1871. Stephan's micrometric position is very accurate, though Esmiol has a typo of 6 minutes in RA in his re-reduction published in 1916.

400/500mm - 17.5" (7/1/89): faint, very small, slightly elongated, bright core. Forms a small triangle with a mag 14 star 40" S and a mag 13 star 52" SE of center. Forms a pair with NGC 6495 5.6' SE.

Notes by Steve Gottlieb