The Milky Way's Giant Neighbor, Andromeda, May Be Slowly Shutting Down New Stars (zmescience.com)

Something has been squeezing the life out of Andromeda’s stellar nurseries. A new study using NASA’s Hubble Space Telescope finds that star formation in Andromeda, the great spiral galaxy nearest to the Milky Way, has declined for the past 500 million years and dropped sharply over the last 40 million. It’s a rare, detailed look at how a galaxy similar to our own changes over time — and hints that a small neighboring galaxy, M32, may have bullied Andromeda into a slower era. Our Closest Galactic Neighbor Andromeda sits about 2.5 million light-years from Earth. On a dark night, it can appear as a faint smudge to the unaided eye. Through Hubble, it becomes a vast body of stars close enough for astronomers to study one star at a time. That makes Andromeda a stand-in for the Milky Way. We live inside our own galaxy, which makes its full shape and history hard to see. NASA has compared the problem to trying to understand New York City while standing in Central Park. Andromeda gives astronomers the outside view. Across two major Hubble surveys—the Panchromatic Hubble Andromeda Treasury (PHAT) and the Panchromatic Hubble Andromeda Southern Treasury (PHAST)—researchers measured about 200 million...