NGC 6656
globular cluster
Messier 22 or M22, also known as NGC 6656 or the Great Sagittarius Cluster, is an elliptical globular cluster of stars in the constellation Sagittarius, near the Galactic bulge region. It is one of the brightest globulars visible in the night sky. The brightest stars are 11th magnitude, with hundreds of stars bright enough to resolve with an 8" telescope. It is just south of the sun's position in mid-December, and northeast of Lambda Sagittarii, the northernmost star of the "Teapot" asterism.
Papers about it
- The complex stellar system M 22: constraining the chemical enrichment from AGB stars using magnesium isotope ratios
- The complex stellar system M 22: confirming abundance variations with high precision differential measurements
- Multiple populations along the asymptotic giant branch: a Gaia+APOGEE study of 22 Galactic globular clusters
- Globular Clusters in the Time of the JWST. I. Survey Design and First Results on Multiple Populations and Beyond