William Herschel discovered NGC 5141 = H III-402 = h1599, along with NGC 5142, on 1 May 1785 (sweep 405) and noted "Two, vF. The time is that of the preceding [NGC 5141]; the second about 3' nf, both cS." JH made two observations, reporting on sweep 331 "pF; R; vsmbM to a star. Has a * 12m preceding. The sp of 2 nebulae [with NGC 5142]."

400/500mm - 17.5" fairly faint, small, small bright core, stellar nucleus, slightly elongated E-W. A mag 13 star is 1.4' WSW. Forms a pair with NGC 5142 2.3' NE.

Notes by Steve Gottlieb