Using advanced infrared imaging, the James Webb Space Telescope (JWST) has captured unprecedented details of the supermassive star cluster Westerlund 1, located around 12,000 light-years from Earth. The findings, released by the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS), provide critical insights into the cluster’s stellar composition and formation processes. Spanning over 6.6 light-years with a mass equivalent to 63,000 suns, Westerlund 1 is the closest supermassive star cluster to Earth and hosts hundreds of massive stars in a dense configuration.

Unique Stellar Features Identified

Mario Giuseppe, team leader at the Palermo Astronomical Observatory, told Space.com that observations were extended to detect brown dwarfs—stars at the lowest end of the mass spectrum. Giuseppe reportedly highlighted the potential to analyse the mass distribution and star formation mechanisms within the cluster. This work is expected to refine the understanding of starburst environments and their influence on planetary development.

JWST’s instruments, the Mid-Infrared Instrument (MIRI) and the Near-Infrared Camera (NIRCam), provided deep imaging capabilities, revealing intricate gas and dust structures surrounding Westerlund 1. This material, believed to result from massive stars’ final evolutionary stages, challenges prior assumptions that young clusters expel such remnants within a million years.

Wider Collaborative Research Efforts

EWOCS has utilised data from other observatories, including the Hubble Space Telescope, ALMA, and NASA’s Chandra X-ray Space Telescope, to complement the JWST findings, as per several reports. Studies on Westerlund 1’s intracluster material and high-energy phenomena, including binary systems and evolved stars, are anticipated in the next few years.

The research, which also involves analysing the slightly younger Westerlund 2 cluster, is expected to shed light on star and planet formation under extreme conditions. These findings have been published in Astronomy & Astrophysics and are available as a preprint on arXiv.