Free Astronomy Magazine March-April 2025

B ackground: The Laser Guide Star (LGS) is launched from the VLT’s 8.2-metre Yepun Telescope and aims at the centre of our galaxy, in the heart of the brightest part of the Milky Way. Above: Two stars have been found orbiting each other in the vicinity of Sgr A*, the supermassive black hole at the centre of the Milky Way. A young binary star system forming and surviving in this extreme gravity means that black holes are not as destructive as we thought. This video summarises the discovery. [G. Hüdepohl (atacamaphoto.com) /ESO] MARCH-APRIL 2025 der destructive conditions. D9, as the newly discovered binary star is called, was detected just in time: it is estimated to be only 2.7 million years old, and the strong gravita- tional force of the nearby black hole will probably cause it to merge into a single star within just one million years, a very narrow timespan for such a young system. ASTRO PUBLISHING 45 “This provides only a brief window on cosmic timescales to observe such a binary system — and we suc- ceeded!” explains co-author Emma Bordier, a researcher also at the Uni- versity of Cologne and a former stu- dent at ESO. For many years, scientists also thought that the extreme environ- ment near a supermassive black hole prevented new stars from forming there. Several young stars found in close proximity to Sagittarius A* have disproved this assumption. The discovery of the young binary star now shows that even stellar pairs have the potential to form in these harsh conditions. “The D9 system shows clear signs of the presence of gas and dust around the stars, which