George Hough discovered NGC 5171 on 5 May 1883 with the 18.5-inch refractor at the Dearborn Observatory. While searching for d'Arrest's comet he recorded "Double. Nebula, round, condensed." The second object actually refers to a star at the northwest edge. Wilhelm Tempel found NGC 5171 just 6 days later and reported it in his 8th discovery list (#2). Ernst Hartwig found it again on 29 Jun 1883 with the 18-inch Merz refractor at the Strasbourg Observatory (AN 2688). These three independent discoveries were made while searching for d'Arrest's comet. While searching for the comet, Hartwig also discovered the close pair NGC 5176 and 5177.

400/500mm - 17.5" (5/27/95): faint, small, round, very small brighter core, faint 40" halo. A faint star is superimposed NW of the core. Forms the NE vertex of a right triangle with two mag 9 stars are 5.3' WSW and 6.8' SW. Brightest of five in a tight group (MKW 11) with NGC 5176 2.9' N, NGC 5177 3.8' N, NGC 5179 2.4' ENE and NGC 5178 7' SSE.

Notes by Steve Gottlieb