One of the largest and brightest star clusters in the Milky Way galaxy is the Arches cluster, and its easy to see why. Lying only 100 light years away from the supermassive black hole that lies in the heart of our galaxy, it formed in an incredibly dense environment.
It lies 25,000 light years from Earth in the constellation Sagittarius, and contains thousands of massive stars, including 160 that are hot, young, and exceptionally more massive than the Sun. Only 1 in 10 Million stars in the galaxy are as bright as these massive central 160 stars. Though it is a young cluster, only a few hundred million years old, it weighs as much as 10,000 solar masses.
The cluster cannot be seen in the sky due to the obscuring effect of huge amounts of gas and dust in the central galactic regions, so astronomers took images in x-ray, infrared, and radio wavelengths since they pass through the thick veils.
X-ray observations have also revealed an envelope of 60 million degree gas surrounding the cluster, likely heated by intense stellar winds from the member stars.
It’s truly a titan of a cluster, and shows astronomers an example of how such massive collections of stars interact and behave as they live their short lives.