December 2007 - Faint stars in globular cluster NGC 6397
Among the many bright stars in NGC 6397 the NASA/ESA Hubble Space Telescope has uncovered what astronomers are reporting as the dimmest stars ever seen in any globular star cluster. Globular clusters are spherical concentrations of hundreds-of-thousands of stars.
Credit:NASA, ESA, and H. Richer (University of British Columbia, Canada)