William Herschel discovered NGC 5590 = H III-417 = h1791, along with NGC 5589, on 1 May 1785 (sweep 405). JH made three observations and recorded (sweep 337) "pB; R; psbM; 15"; the sf of 2; moonlight." In addition, h1785 = NGC 5580 is a duplicate observation with a 1 min error in RA. So, NGC 5590 = NGC 5580.

300/350mm - 13.1" (4/10/86): fairly faint, small, round, bright core, stellar nucleus. Forms a pair with NGC 5589 4.8' NW. NGC 5579 lies 15' W. Member of the NGC 5557 group (LGG 378).

Notes by Steve Gottlieb