Astronomers find two distinct star clusters in UBC 63
A study by researchers from India and abroad reveals that a previously identified single star cluster is actually two separate systems.
A team of international astronomers and researchers from India has discovered that UBC 63 is composed of two separate star clusters rather than one. According to The Hindu, the group of stars, located approximately 4,892 light years from Earth, was previously thought to be a single cluster.
The researchers, including a Department of Science and Technology (DST) INSPIRE Senior Research Fellow from Gauhati University and members of the Indian Institute of Astrophysics (IIA), used data from the European Space Agency’s (ESA) Gaia mission. They identified the two systems as UBC 63A and UBC 63B.
Analysis of the brightness and colours of the stars showed two different sequences in a colour-magnitude diagram. Using machine learning and dynamical simulations, the team confirmed that UBC 63A is about 21 million years old, while UBC 63B is approximately 562 million years old.
DST stated that this age gap proves the two systems did not start as one cluster. Simulations suggest the clusters were separated by about 60 parsecs when the younger one formed, but they came within 7 parsecs of each other roughly 6 million years ago.
The two clusters are currently about 26 parsecs apart and are not gravitationally bound. The study indicates they are moving away from each other following their close encounter.