John Herschel discovered NGC 5279 = h1665a on 4 May 1831 and described a "vF; double neb; pos = 73° by micrometer." WH discovered the brighter southwestern component on 14 Apr 1789. JH only included only a single entry in the GC (3639), though described this system as a double or bi-nuclear.

Lawrence Parsons (the 4th Earl of Rosse) resolved the pair again on 2 May 1872 and noted a "D neb, sp one B, pos 71.8°, dist 39". In the NGC, Dreyer equated NGC 5279 with h1665a and listed LdR* (Lawrence Parsons) in the "Other Observers" column to acknowledge JH's prior discovery.

400/500mm - 17.5" (6/18/93): very faint, very small, round, 20" diameter, even surface brightness. Located just off the east edge of larger and brighter NGC 5278. On photos NGC 5279 appears to be embedded at the end of a spiral arm of NGC 5278.

600/800mm - 24" (6/21/20): at 375x: fairly faint, small, round, 15"-20" diameter, stellar nucleus. Fainter component of an interacting pair (Arp 239) with NGC 5278 [36" between centers].

900/1200mm - 48" (5/3/19): at 545x and 813x: fairly bright, small, brighter nucleus, 0.4'x0.3'. Spiral structure evident with an arm faintly visible on the east side extending north and merging into the dim tidal bridge to the north side of NGC 5279. The tidal bridge was seen as low surface brightness haze connecting to an easy spiral arm on the north side of NGC 5278.

Notes by Steve Gottlieb