Astronomers Discover First Binary Star Near Milky Way’s Supermassive Black Hole

Credit:

ESO/F. Peißker et al., S. Guisard

Astronomers discovered a pair of stars orbiting each other, known as a binary star, has been found close to Sagittarius A*, the supermassive black hole at the center of our galaxy. This is the first time such a stellar duo has been observed in this extreme environment. The finding, made using the European Southern Observatory’s Very Large Telescope (ESO’s VLT), provides insights into how stars can survive in regions dominated by immense gravitational forces. It also raises the possibility of finding planets near the black hole.

Binary stars are common in the universe, but scientists had not expected them to exist so close to a supermassive black hole, where the intense gravity tends to destabilize such systems. The newly discovered binary, named D9, offers a rare glimpse into these extreme conditions. D9 is thought to be just 2.7 million years old, and it is unlikely to remain a pair for much longer. The gravitational pull of the nearby black hole is expected to cause the two stars to merge into one within about a million years.

The discovery of D9 also challenges long-standing assumptions that the hostile environment near a supermassive black hole prevents star formation. Over the years, scientists have found several young stars near Sagittarius A*, and now this binary system suggests that even stellar pairs can form in these harsh conditions. Observations show that D9 is surrounded by gas and dust, indicating it may have formed close to the black hole itself.

D9 was identified in a dense region of stars and other objects near Sagittarius A*, known as the S cluster. This cluster is home to enigmatic "G objects," which appear to behave like stars but resemble clouds of gas and dust. While studying these G objects, the researchers noticed unusual changes in the velocity of D9, which revealed it to be a binary system. Data collected over 15 years confirmed this discovery.

The presence of D9 also offers clues about the mysterious G objects. Researchers suggest these might be unmerged binary stars or material left over from stars that have already merged.

The nature of many objects near Sagittarius A* remains unclear, but future observations with advanced instruments like the GRAVITY+ upgrade for the VLT and the METIS instrument on ESO’s Extremely Large Telescope (ELT) could provide answers. These tools will enable even more detailed studies of the Galactic center, possibly uncovering more binary systems and young stars. This discovery also raises hopes for detecting planets in this region, as they often form around young stars like those in D9.

Reference: ESO News