The Chandelier Cluster: A Window into the Ancient Milky Way
The NASA/ESA Hubble Space Telescope has captured a stunning new image of globular cluster NGC 6723, also known as the Chandelier Cluster. Located 27,000 light-years away in the constellation Sagittarius, this dense swarm of stars contains some of the oldest stellar objects in the Milky Way, with ages exceeding 10 billion years.
Globular clusters are dense, spherical collections of tens of thousands to millions of stars, all bound tightly together by gravity. The Milky Way is home to over 150 of these ancient stellar cities.
Hubble's Deep Dive into an Ancient Super-Cluster
The observations of NGC 6723 were conducted as part of Hubble program #10775 (PI: Sarajedini), a sweeping survey of 65 globular clusters using visible and near-infrared light. A follow-up program (#13297, PI: Piotto) then utilized ultraviolet light to investigate the chemical variations and star formation history within these clusters.
The research on NGC 6723 revealed a surprising and complex history: evidence of two distinct, closely-spaced periods of star formation. The second burst of stellar birth occurred within 634 million years of the first. This places the cluster’s overall age at over 10 billion years old.
"For NGC 6723, researchers found evidence of two closely-spaced periods of star formation, with the second occurring within 634 million years of the first."
A Legacy of Scientific Discovery
The data from these Hubble surveys has proven to be a treasure trove for astronomers, contributing to several hundred published research papers. The findings have provided critical insights into:
- The precise ages of globular clusters
- The migration of stars within the Milky Way
- The formation history of these ancient, bound systems
The image of the Chandelier Cluster serves as a beautiful reminder that even the oldest objects in our galaxy hold secrets yet to be illuminated.