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So far, scientists believe there is no binary star system near Sagittarius A*, the supermassive black hole at the center of the Milky Way. However, new research suggests that one such system of gravitationally bound stars exists in the S Cluster, a group of high-velocity stars surrounding Sagittarius A*.
The research results were published in nature communications Journal on Tuesday, December 17, 2024.
Scientists named this system D9 because of its similarities to the G Object, a strange celestial body that “looks like gas but behaves like a star.” The study also predicts that the stars will live about 3 million years before merging with each other due to their continued interaction with Sagittarius A*.
The two stars in the D9 system take approximately 372 days to complete one orbit. Given their size, this orbit is stable enough that the black hole’s overwhelming gravity won’t tear them apart. They are also about 1.59 astronomical units (AU) apart, well below the tidal interference radius of about 42.4 AU. The tidal disruption radius is the distance at which a star can be torn apart by a supermassive black hole, triggering a tidal disruption event.
The two stars in the D9 system are Herbig Ae/Be stars and T-Tauri stars.
The discovery shows that although this binary system has not been discovered before, these stars can survive in the S cluster near the supermassive black hole for a very long time – about a million years in the case of Sagittarius A*.
This is also important because the binary system that exists with G objects allows us to partially resolve the “uncertainty” of G objects. Since the D9 system is expected to be merged, it is possible that these G objects are merged binary systems.
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Published – December 18, 2024 at 5:48 pm (IST)