Uncovering the Complexities of Messier 92's Stellar Populations

Astronomers have used the James Webb Space Telescope and the Hubble Space Telescope to observe Messier 92, a metal-poor globular cluster located 26,700 light years away in the constellation of Hercules. The observations have provided crucial information regarding multiple stellar populations in this cluster, revealing that it hosts at least two stellar generations of stars named 1G and 2G. The observations identified the three previously reported stellar groups, namely 1G, 2GA and 2GB, which share similar radial distributions of the proper motion dispersion. The helium abundances of 2GA and 2GB stars were found to have higher mass fractions than that of the 1G stars.