Quick facts
What it is: The star cluster Westerlund 2
Where it is: 20,000 light-years from Earth, in the constellation Carina
When it was shared: Dec. 19, 2025
Bordered by orange and brown clouds of gas and dust and filled with shimmering stars, this new image from the James Webb Space Telescope appears to show a portal to a cosmic wonderland.
The sparkling cluster is compact, measuring between 6 light-years and 13 light-years in diameter, and it is home to approximately 3,000 stars, according to a statement from the European Space Agency. Seen here at a young age of about 2 million years, this cluster contains some of the hottest, brightest and most massive stars in our galaxy.
Westerlund 2 was also captured by the Hubble Space Telescope 10 years ago to commemorate Hubble’s 25th anniversary in orbit. That image, created using visible light and some near-infrared data, revealed the complex features of the cluster and its surrounding nebula, showcasing a stunning landscape of pillars, ridges, and valleys of dust.
Now, the James Webb Space Telescope has revealed an even more vibrant view of the cluster, which is teeming with bright young stars. This latest portrait combines infrared data from the telescope’s Near-Infrared Camera and Mid-Infrared Instrument.
The stunning image highlights not only the young, massive stars but also the clouds and walls of dust shaped by their intense light. These sculpted regions are surrounded by wisps of orange and red gas, brilliantly illuminated by the powerful light of the nearby stars.
The entire scene is interconnected by a network of blue and pink wisps that appear to be material drifting off the scene. Several tiny stars look like they have just begun shining, still embedded in the thick cloud in which they formed. Larger and brighter stars that are much closer to us display an eight-pronged diffraction pattern created by the interaction of starlight with the telescope’s instruments.
The twinkling display of countless stars is a result of a continuous cycle of star formation in which the baby stars in the stellar nursery blast out intense radiation that then heats the surrounding nebula and triggers new stars to form.
The new observations, taken across a wide range of infrared wavelengths, include bands that are sensitive to methane and polycyclic aromatic hydrocarbon (PAH) emission. While PAH emission traces heated gas and dust, methane traces low-mass cold objects. As a result, astronomers identified a population of brown dwarfs — or “failed stars” — including objects only about 10 times the mass of Jupiter.
Brown dwarfs are peculiar objects that straddle the line between stars and planets. They have masses in between those of typical stars and those of planets, ranging between 10 and 90 times the mass of Jupiter. However, they do not have enough mass to trigger nuclear fusion in their cores. The James Webb telescope’s new observations could reveal insight into the different stages in a star’s life and how planet-forming disks around massive stars work.
For more sublime space images, check out our Space Photo of the Week archives.
