William Herschel discovered NGC 517 = H III-168 = h114, along with NGC 515, on on 13 Sep 1784 (problematic sweep 271 using Beta Andromedae as the reference star). WH simply noted "Two, both stellar" and his single position (marked uncertain) is about 35 sec of RA east of NGC 515 = UGC 956. JH made the single observation "pB; R". Heinrich d'Arrest measured a pretty accurate position (3 nights). See Corwin's notes.

300/350mm - 13.1" (8/8/86): fairly faint, small, elongated 2:1 SSW-NNE. Appears slightly brighter than NGC 515 3' NNW.

600/800mm - 24" (10/4/13): moderately to fairly bright, moderately large, elongated 2:1 SSW-NNE, ~45"x22", well concentrated with a bright core. Forms a pair with NGC 515 2.9' NNW. Member of the NGC 507 Group.

Notes by Steve Gottlieb