Free Astronomy Magazine July-August 2026

JULY-AUGUST 2026 stars are born in a collapsing cloud, strong stellar winds, harsh ultravio- let radiation and the supernova ex- plosions of massive stars eventually disperse the cloud, ending star for- mation before all the gas is used up. Once the cloud of gas a star cluster was born in is gone, its light can bear down on other star-forming re- gions in the galaxy, too. This process is called stellar feedback, and it means that most of the gas in a galaxy never gets used for star for- mation. Researching how star clus- ters develop, then, can answer questions about star formation at a galactic scale. Studies of the closest star-forming regions, in the Milky Way galaxy and the dwarf galaxies that orbit it, allow us to dissect star clusters in the smallest details, but our position in the disc of our galaxy means only a few such regions are visible to us. The more massive star clusters emerge more quickly by NASA/ESA/CSA Bethany Downer A stronomers have long known that understanding how star clusters come to be is key to unlocking other secrets of galactic evolution. Stars form in clusters, cre- ated when clouds of gas collapse under gravity. As more and more