William Herschel discovered NGC 3589 = H III-921 = h839 on 9 Apr 1793 (sweep 1039) and noted "eF, pL, E." John Herschel recorded on 25 Mar 1832 (sweep 406), "vF; L; vglbM; 45"; situated in the centre of gravity of a triangle of 3 large stars 5' distance." His position was accurate.

400/500mm - 17.5" (3/19/88): faint, moderately large, oval ~SW-NE, diffuse. Located just west of the line connecting mag 7.5 SAO 15447 4' NNE and mag 8.6 SAO 15449 5' SE.

Notes by Steve Gottlieb