William Herschel discovered NGC 5209 = H III-10 = h1628 on 23 Jan 1784 (sweep 108) and recorded "Two very feeble nebula [with III-9 = NGC 5208]. They are eF." "Two. Both vF and vS." His position is poor. JH made two observations, providing a fairly accurate position.

400/500mm - 17.5" (5/27/95): faint, fairly small, round, 1.0' diameter. Broad, weak concentration with no distinct core. Fainter of a pair with NGC 5208 3.7' WSW.

600/800mm - 24" (6/1/13): at 225x appeared moderately bright, fairly small, round, 0.6' diameter, sharply concentrated with a very bright, 0.3' core that increases to the center. Forms a pair with NGC 5208 3.7' WSW with CGCG 045-011 3.0' E. Also, CGCG 045-012 is 4.7' NNE.

Notes by Steve Gottlieb