Hubble Spies Starry Chandelier

The subject of today’s NASA/ESA Hubble Space Telescope image is an ancient inhabitant of our galaxy. This sparkling scene features a globular cluster : a collection of tens of thousands to millions of stars, all tightly bound together under the influence of gravity. There are more than 150 globular clusters in our galaxy, though there may be others still undiscovered, hidden from view by dust or densely packed fields of stars. This globular cluster, NGC 6723, sometimes called the Chandelier Cluster, is much like its namesake because it sparkles with countless lights. However, each ‘lightbulb’ in this chandelier is an individual star 27,000 light-years away in the constellation Sagittarius (the Archer). Globular clusters like NGC 6723 contain some of the oldest stars in our galaxy. These clusters have ages that often exceed 10 billion years old, and some are nearly as old as the universe itself. Astronomers think globular clusters are some of the first structures that formed in our galaxy, coalescing potentially billions of years before the thin disk of stars in which our Sun orbits. The details of how globular clusters formed, however, are not yet certain. Astronomers initially thought that all stars in a globular cluster formed at the same time in a single flourish of star formation. This would mean that all stars in a globular cluster would be the same age and made of the same mixture of chemical elements. …