John Herschel discovered NGC 6209 = h3645 on 28 Jun 1835 and recorded "eF; pL; vgvlbM; 2' dia; quite hopeless, except in the clearest and finest night, and with the mirror bright.". The next night he confirmed the observation: "Found in the place, and viewed. It is very visible, and PD is right per index." His position is accurate.

600/800mm - 24" (4/4/08 - Magellan Observatory, Australia): fairly bright, fairly large, oval 3:2 SSW-NNE. I noticed a faint star or knot at the south end. A mag 11.5 star is located 4' and a couple of fainter stars are at the SW and SE ends.

Notes by Steve Gottlieb