Exploding stars aren't the reason galaxies stop making new stars—it's actually just because the whole galaxy is spinning too fast.
arXiv · March 16, 2026 · 2603.12821
Why it matters
For decades, astronomers thought supernova explosions were the 'brakes' that prevented galaxies from burning through their fuel too quickly. This study suggests that the simple act of a galaxy rotating is actually far more effective at keeping gas stable, forcing a rethink of how the universe's smallest galaxies grow.
From the abstract
Stars form in cold, dense clouds embedded in galactic discs, but whether their formation is primarily regulated by gravitational collapse, turbulence, or stellar feedback remains unclear. Using four high-resolution dwarf galaxy simulations with and without supernova (SN) feedback and magnetic fields, we test how feedback regulates the supply of dense gas and, consequently, the star formation rate (SFR). Although the SFR does increase when SNe are turned off, this increase is only by a factor of