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Astronomers have spotted a star tearing through the Milky Way that appears to have been flung outwards following an encounter with the supermassive black hole at our galaxy鈥檚 heart.

This 鈥榟yper-velocity star鈥� has been named S5-HVS1. It is travelling through the galaxy at a blistering speed of more than 1700 kilometres per second.

We have seen other stars that are travelling faster than this, but those are dying stars thought to have been blasted outwards by supernova explosions. In contrast, S5-HVS1 seems to have been set on its way by a close encounter with the supermassive black hole at the centre of our galaxy, known as Sagittarius A*.

The star was found by the Southern Stellar Stream Spectroscopic Survey, which has been observing tens of thousands of stars using the Anglo-Australian Telescope in New South Wales, Australia.

The team of researchers behind the work suggest that the star might once have been part of a pair of stars orbiting one another. Then they got close to our galaxy鈥檚 central black hole, at which point the intense gravity would have ripped the system apart, flinging S5-HVS1 outwards and onto its current course.

It has always been hard to trace where other hyper-velocity stars started their journey. But that鈥檚 not the case for this one.

鈥淲e can calculate quite precisely where this star is coming from,鈥� says Sergey Koposov at Carnegie Mellon University, US, who led the work. 鈥淎nd it looks like it is coming from a tiny region that includes the galactic centre.鈥�

We could learn a lot from studying this object and others like it. For example, by tracking the star鈥檚 route, we might see how it was affected by the halo of dark matter around our galaxy, and so discern more about what that halo is like. 鈥淭his observation is extremely interesting for galactic centre research,鈥� says astrophysicist Alessia Gualandris, at the University of Surrey, who wasn鈥檛 involved in the work.

S5-HVS1 is destined for a lonely swansong however. At its current speed it will spend its final days sailing through intergalactic space. Indeed, the researchers estimate that upon its death it will be several million light years away.

Reference:听