History

This globular cluster was discovered by French astronomer Nicolas-Louis de Lacaille (also: de la Caille) in 1751-1752 with a 1/2" telescope at 8x, during his expedition to the Cape of Good Hope. He listed it as Lac III-11 and noted: «Small star involved in a nebulosity.» ^[8]

Scottish astronomer James Dunlop independently found this globular on 28 June 1826 using his 9-ich speculum reflector. He made four observations, listed it as Δ 366 and noted: «A pretty large nebula, extended nearly in the parallel of the equator, brightest and broadest in the middle; a group of very small stars in the middle give it the appearance of a nucleus, but they are not connected with the nebula, but are similar to other small stars in this place which are arranged in groups. The nebula is resolvable into stars.» ^[50]

John Herschel listed the cluster as h 3692. He observed it three times. His first observation was on 8 July 1834 (sweep 468) and he noted: «Globular cluster; fine; large; bright; round; gradually brighter to the middle; not very compressed; 5' diameter, but stragglers extend a great way. In the middle is a more compact group of much smaller stars. The stars at circumference are larger than in the middle; at north following border is a double star.» ^[11]