A stunning new composite image, released by NASA on March 19, 2026, combines X-ray and infrared vision to reveal the chaotic beauty of the Westerlund 2 star cluster.
Location and Characteristics
Westerlund 2 is located approximately 20,000 light-years from Earth in the constellation Carina, within the star-forming nebula Gum 29. The cluster is a compact stellar grouping measuring between 6 and 13 light-years in diameter and hosts approximately 3,000 stars.
The stars in Westerlund 2 are estimated to be between one and three million years old. The cluster contains some of the galaxy's hottest, brightest, and most massive stars.
Imaging Details
The composite image combines X-ray data from the Chandra X-ray Observatory (shown in pink) with infrared data from the James Webb Space Telescope (JWST, shown in red, orange, green, cyan, and blue). The JWST data was captured using the telescope's Near-Infrared Camera and Mid-Infrared Instrument.
The image shows the cluster surrounded by dust clouds and features wisps of orange and red gas, along with blue and pink material. Young, massive stars are visible alongside smaller stars still embedded in their formation clouds. The surrounding clouds and walls of dust show evidence of sculpting by intense light from the cluster's stars.
The star cluster exhibits a continuous cycle of star formation, in which young stars emit radiation that heats the nebula.
Scientific Findings
The new JWST observations included infrared bands sensitive to methane and polycyclic aromatic hydrocarbon emission. These observations enabled astronomers to identify a population of brown dwarfs within the cluster.
Brown dwarfs are objects with masses between those of typical stars and planets (approximately 10 to 90 times Jupiter's mass) that lack sufficient mass to initiate nuclear fusion in their cores.
Some of the identified brown dwarfs have masses approximately 10 times that of Jupiter.
Previous Observations
The Hubble Space Telescope previously observed Westerlund 2 approximately a decade ago, providing an image in visible and near-infrared light.
Credits
X-ray: NASA/CXC/SAO/Sejong Univ./Hur et al; JWST: ESA/Webb, NASA & CSA, V. Almendros-Abad, M. Guarcello, K. Monsch, and the EWOCS team. Image Processing: NASA/CXC/SAO/L. Frattare and K. Arcand.