This space cluster looks like ‘winter’ wonderland

NGC 6357 is a “cluster of clusters,” containing at least three clusters of young stars, including many hot, massive, luminous stars.

The space between stars contains bubbles, or cavities, that have been created by radiation and material blowing away from the surfaces of massive stars, plus supernova explosions.

Hot, young stars in the cluster emit radiation that energizes the cooler gas in the cloud that surrounds them.

This image combines X-ray data from NASA’s Chandra X-ray Observatory and the ROSAT telescope (purple), infrared data from NASA’s Spitzer Space Telescope (orange), and optical data from the SuperCosmos Sky Survey (blue) made by the United Kingdom Infrared Telescope.