A Rare Star Escapes the Supermassive Black Hole at the Heart of the Galaxy

The center of the galaxy isn't the kind of place stars emerge from in one piece. sripfoto/Shutterstock

This may be the luckiest star in the universe.

After all, it's not every day that anything escapes the clutches of a supermassive black hole, much less a massive celestial body.

In fact, in a research paper published online in Cornell's arXiv, scientists suggest the "hyper-velocity" star dubbed S5-HVS1 may be the first one detected exiting from a black hole.

And what an exit it was. In the paper, partly titled "The Great Escape," researchers suggest it's moving at the ferocious rate of more than 1,000 miles per second.

Surviving a Black Hole

The star likely needed every ounce of that momentum to make its "great escape" from no less than the supermassive black hole that lurks at the heart of our own galaxy, the Milky Way. That area of space is better known for devouring stars than setting them free.

And that would be largely due to the supreme reign of a supermassive black hole, dubbed Sagittarius A* (pronounced "Sagittarius A star") — a gravitational golem with a mass around 4 million times that of our sun.

Researchers made the "serendipitous discovery" while working on the Southern Stellar Stream Spectroscopic Survey, a collaboration of more than 30 international scientists that maps stellar streams in the Milky Way.

One of those streams suggested a star was hurtling outward from the very heart of the galaxy.

"When integrated backwards in time, the orbit of the star points unambiguously to the Galactic Centre, implying that S5-HVS1 was kicked away from Sgr A* with a velocity of 1,800 km/s and travelled for 4.8 M years to the current location," the study abstract reads.

The Star's Future

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)

And it's not just that the star muscled its way out of the grasp of Sgr A*. The galaxy's core happens to be riddled with smaller but still powerful black holes. In fact, a recent study pegs the black hole population at the heart of our galaxy at somewhere around 10,000.

So what does a black-hole dodging star do for an encore — besides, of course, spending the next few millions years congratulating itself?

Even this star appears a little directionless now that its long struggle with dark powers is at an end. According to the researchers, it has spent the last 4.8 million years roaring through space. Maybe that's how long it takes — and how fast one has to go — before being comfortable with a black hole in the rearview mirror.