Hubble Data Shows Star Formation Sharply Declining in Andromeda Galaxy

Across 2.5 million light-years of cosmic distance, the Andromeda Galaxy is quietly dimming its stellar fires — a process astronomers at the University of Washington have now traced in remarkable detail using NASA's Hubble Space Telescope. By reading the colors and lifespans of 190 million individual stars like layers of ancient sediment, researchers have found that Andromeda's rate of star formation has fallen to just one-fifth of what it was half a billion years ago, with the steepest drop occurring in the most recent 40 million years. This measured fading, possibly nudged along by a gravitat