The Milky Way contains many young star clusters and associations that each hold hundreds or even thousands of hot, massive, young stars known as Type O and Type B stars. The star cluster Cygnus OB2 is home to more than 60 O-type stars and around a thousand B-type stars.
Observations of Cygnus OB2 using NASA’s Chandra X-ray Observatory have detected the X-ray emissions from the hot outer atmospheres (coronas) of young stars in the cluster. About 1,700 X-ray sources were detected, around 1,450 of which are thought to be stars in the cluster. This image of the cluster was assembled with X-ray data from Chandra (blue), infrared data from NASA’s Spitzer Space Telescope (red), and optical data (orange).
Image Credit: NASA