John Herschel discovered NGC 2172 = h3015 on 31 Jan 1835 and recorded "vF; L; R; gbM; 2'." On a second sweep he recorded "pF; R; lbM; 50"." His mean position (two sweeps) is at the south edge of the cluster.

James Dunlop's D 197, found on 27 Sep 1826, is possibly an earlier discovery though the cluster may be too faint for him to pick up. He described a "small faint round nebula" and his position was off by 12' to the NE.

Pietro Baracchi picked up this cluster on 3 Jan 1886 while observing the nearby clusters with the 48" Melbourne telescope and called it "a nebulous patch, small, a little elongated and faint, with two stars involved in it." His diagram shows a third star (called 17th mag) just off the SE edge. He labeled this cluster "(A)" and assumed it was a new discovery.

600/800mm - 24" (4/11/08 - Magellan Observatory, Australia): At 200x this LMC cluster appeared moderately bright, fairly small, ~0.8' diameter, irregular, a couple of stars are resolved within the glow. At 350x, the glow is clumpy with four stars resolved with the brightest star at the SE edge. Located 10' SE of NGC 2164 and 11' ESE of NGC 2159. Fourth of four (including NGC 2156) in a 16' circle.

Notes by Steve Gottlieb