Messier 23, also known as NGC 6494, is an open cluster of stars in the southern constellation of Sagittarius. It was discovered by Charles Messier on June 20, 1764. M23 can be found with binoculars or a modestly sized telescope. The cluster is positioned in front of "an extensive gas and dust network", although it is unclear if there is an association between the two. It is located near the ecliptic and thus is subject to lunar occultations.