A 13 billion-year-old cosmic chandelier! Too dense to count [Amazing Universe]

The Hubble Space Telescope has captured a stunning image of NGC 6723, a globular cluster also known as the 'Chandelier Cluster,' located in the constellation Sagittarius. Situated approximately 27,000 light-years from Earth, this celestial formation is characterized by a dense concentration of stars, numbering from tens of thousands to millions, all bound together by gravity.

Globular clusters are considered among the earliest structures to form in the Milky Way galaxy. The stars within NGC 6723 are ancient, with some exceeding 10 billion years in age, nearly as old as the universe itself. The cluster's dense core makes it challenging to observe individual stars, contributing to its spectacular, chandelier-like appearance.

While astronomers once believed globular clusters formed uniformly at a single time, new research utilizing Hubble's advanced imaging capabilities has revealed a more complex formation process. By analyzing 65 globular clusters, including NGC 6723, with both visible light and near-infrared cameras, scientists observed that more massive stars tend to congregate at the center, while smaller stars are pushed towards the periphery.

Further analysis using Hubble's ultraviolet detectors provided more precise dating for NGC 6723. The findings indicate that the cluster formed in two distinct episodes, occurring approximately 12 to 13 billion years ago, with a gap of about 634 million years between these formation periods. The exact number of stars within the Chandelier Cluster remains difficult to estimate due to their extreme density, but it is believed to be in the hundreds of thousands.