nasa: Say hello to globular cluster 47 Tucanae This glittery spray of ancient stars is ab
nasa: Say hello to globular cluster 47 Tucanae This glittery spray of ancient stars is about 16,700 light-years away from Earth toward the constellation Tucana. Globular clusters like this one are isolated star cities, home to hundreds of thousands of stars that are held together by their mutual gravity. And like the fast pace of cities, there’s plenty of action in these stellar metropolises. The stars are in constant motion, orbiting around the cluster’s center. Past observations have shown that the heavyweight stars tend to crowd into the “downtown” core area, while lightweight stars reside in the less populated suburbs. But as heavyweight stars age, they rapidly lose mass, cool down and shut off their nuclear furnaces. After the purge, only the stars’ bright, superhot cores – called white dwarfs – remain. This weight loss program causes the now lighter-weight white dwarfs to be nudged out of the downtown area through gravitational interactions with heftier stars. Until these Hubble observations, astronomers had never seen the dynamic conveyor belt in action. The Hubble results reveal young white dwarfs amid their leisurely 40-million-year exodus from the bustling center of the cluster. Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com. -- source link