Black Hole Boots a Star Clear Across the Milky Way — And It's Moving Incredibly Fast

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An illustration showing the star S5-HVS1 being evicted from the heart of the Milky Way galaxy. Still from YouTube/Sergey Koposov

There's really no arguing with a time-and-space-bending vortex, especially the supermassive specimen at the heart of our Milky Way galaxy known as Sagittarius A*. So it doesn't much matter what one star did to offend our local black hole. Only that there will be no appeal — and the punishment lasts for a virtual eternity.

That's the situation a star recently spotted by astronomers finds itself in. Researchers say it was kicked out of the heart of our galaxy and banished with such ferocity that it's bound to leave the Milky Way altogether.

And it's likely that old tyrant Sagittarius A* made the call.

In research published in the Monthly Notices of the Royal Astronomical Society, astronomers describe the ultimate shooting star — one that appears to have been flung clear across the galaxy.

"We traced this star's journey back to the center of our galaxy, which is pretty exciting," notes study co-author Gary Da Costa of The Australian National University in a news release. "This star is travelling at record-breaking speed — 10 times faster than most stars in the Milky Way, including our Sun."

In fact, at 3,728,227 mph, it's the third fastest star ever measured — and the first hypervelocity star ever detected exiting the galactic heart.

The star, dubbed S5-HVS1, should catapult right out of our galaxy in the next 100 million years.

Along the way, scientists may glean a few details from its dramatic banishment.

"The two really special features of this star, though, are that its speed is much higher than other similar stars that were previously discovered and it's the only one where we can be almost certain that it has come directly from the center of the Milky Way," Da Costa explains. "Together those facts provide evidence for something called the 'Hills mechanism' which is a theorized way for the supermassive black hole in the center of the Milky Way to eject stars with very high velocity."

But this star's crime may forever remain a mystery.

Was it something the star did? Maybe. But more likely, astronomers say, it was the company it kept. About 5 million years ago, the star likely had a mate in another star. Together, they formed a binary system, essentially two stars that revolve around each other for life.

And let nothing come between them. Except for a black hole.

A close-up photo of the black hole at the heart of Sagittarius A*.
A close-up photo of the black hole at the heart of Messier 87. (Photo: National Science Foundation)

Scientists suggest the binary system may have wandered a little too close to the cranky chasm at the heart of the Milky Way. And the black hole's punishment was as swift as it was severe.

"If such a binary system approaches a black hole too closely, the black hole can capture one of the stars into a close orbit and kick out the other at very high speed," study co-author Thomas Nordlander of Australian National University, explains.

Basically, Sagittarius A* broke up that lifelong relationship with devastating authority. It put one of the stars on its dinner plate, and spit the other across the galaxy, where its lonesome, never ending sentence is just beginning.

"In astronomical terms, the star will be leaving our galaxy fairly soon," Da Costa adds. "And it will likely travel through the emptiness of intergalactic space for an eternity."

You can almost hear a grumble escape the inescapable maw at the heart of our galaxy: Good riddance.