Édouard Stephan discovered NGC 5759 = St XI-29 on 7 Jun 1880. His position is accurate.

400/500mm - 17.5" (7/17/01): very faint, fairly small, elongated 2:1 NW-SE, 0.8'x0.4', low even surface brightness. Forms a pair with difficult CGCG 076-042 3.4' S. This is a double system with a compact companion off the NW end but it was not resolved. Located 13' S of NGC 5758 in a group.

600/800mm - 24" (7/10/18): at 225x; fairly faint, fairly small, irregularly round. Contains a bright core that is offset to the southeast side and a faint halo that extends only northwest of the core! CGCG 076-042, situated 3.4' S, appeared faint, small, elongated 3:2 or 2:1 SSW-NNE, ~25"x15", very small bright nucleus.

NGC 5759 form an interacting pair (connected with a tidal bridge) with LEDA 200319, just 45" NNW. At 375x, the companion was very faint, round, only 5" diameter, and could be barely held continuously with averted vision. A mag 15.2 star is 45" N.

Notes by Steve Gottlieb