Young double-star system discovered near our Galaxy’s giant black hole
By Daniel Clery, Science.
Excerpt: Astronomers studying the murky center of our Milky Way Galaxy have discovered something they never expected: a pair of young stars orbiting each other near the supermassive black hole that is our Galaxy’s dark heart. The observation—reported today in Nature Communications—comes as a surprise because astrophysicists had thought the black hole’s intense gravity would either rip the stars in such a pair apart or squash them together. But the new object, dubbed D9, shows that such a “binary” can survive, at least briefly, near the black hole, and it could help explain other mysterious objects in the vicinity. ...For many years, two teams, in California and Germany, monitored the closest of those stars. About 20 years ago, both proved the star’s eccentric, high-speed orbit could only arise if it was circling a compact object with extreme mass—a black hole. For that work, the teams’ leaders, Reinhard Genzel of the Max Planck Institute for Extraterrestrial Physics (MPE) and Andrea Ghez of UCLA, shared part of the 2020 Nobel Prize in Physics. ...Evidence for the newly reported binary came as it often does for such systems, in a warble in wavelength of starlight. Astronomers led by Florian Peißker of the University of Cologne ...with the European Southern Observatory’s Very Large Telescope ...noticed one object’s characteristic emission line shifted slightly at different times....