For the first time ever, astronomers find 'twin stars' orbiting the Milky Way’s supermassive black hole

A laser points toward the core of our galaxy, illuminating the brightest region of the Milky Way. (ESO)

Astronomers have made a major discovery at the centre of our galaxy. A binary star system has been found orbiting the supermassive black hole, Sagittarius A*. This discovery, made by a team led by Florian Peißker from the University of Cologne, offers fresh insight into the Milky Way's extreme environment.

The binary system, named D9, is located 27,000 light years from Earth. Its discovery, announced in Nature Communications, provides answers to a cosmic mystery. Astronomers have long wondered why some stars move much faster than others.

Unravelling the Mystery of Hypervelocity Stars

A binary star system consists of two stars orbiting each other. While our Sun is a solitary star, most stars in the Milky Way belong to binary or multiple systems. Binary systems are valuable to astronomers, as they provide data about the stars' masses.

This image highlights the location of the newly identified binary star system, D9, orbiting Sagittarius A*, the supermassive black hole at the heart of our galaxy. (Image: ESO)

Before this discovery, scientists had speculated that binary systems existed near supermassive black holes. But observing one has always been difficult. The team used the European Southern Observatory's Very Large Telescope to detect the stars' movement. By measuring the starlight's shift, they identified an orbit.

The system is approximately 2.7 million years old. This suggests the stars did not form in Sagittarius A*’s extreme environment. They likely arrived there later, showing how black holes can affect surrounding stars. According to The Conversation, the discovery also helps to explain the phenomenon of hypervelocity stars.

Hypervelocity stars are travelling at speeds over 1,000 kilometres per second. Most stars orbit the centre of the galaxy at speeds of around 200 kilometres per second. However, hypervelocity stars move much faster, having been ejected from their original orbits. This may occur when stars, once part of a binary system, get too close to the black hole.

Sagittarius A: The Milky Way’s Powerful Heart*

The newly discovered binary star system around Sagittarius A* adds weight to this theory. By observing this system, astronomers can gain insights into how hypervelocity stars are formed. It’s an important step in unraveling the mysteries of our galaxy’s heart.

The centre of the Milky Way remains a fascinating area of study. This new discovery offers fresh clues about the forces at play. With more observations, astronomers are sure to uncover even more about this complex region.