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Scientists Have Figured Out How Fast The Fastest Star In The Galaxy Is

And it's going a mere 2.7 million miles per hour.

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A speeding star in our galaxy is the fastest recorded star in the Milky Way Galaxy.

Dan Meth / BuzzFeed

In a new study published in Science, astronomers used two telescopes in Hawaii to determine that the white dwarf is going about 1,200 kilometers per second. (In case you forgot, white dwarves are dense, burned-out stars.)

In other words, that's about 2,684,320 miles per hour! (Which is much faster than a speeding bullet.) With some quick math, that means it could go from Earth to the moon in a little over five minutes.

It's so fast, it'll escape the Milky Way's gravity.

Dan Meth / BuzzFeed

Dubbed US 708, the star blipped on astronomers' radar a decade ago. Unlike other stars, it's not harnessed in an orbit, which is why scientists refer to it as unbound, or a hypervelocity star (HVS) — and why it can fling itself right out of our galaxy.

Our sun and solar system, on the other hand, orbit the Milky Way's center at a velocity of about 230 kilometers per second (or 515,000 mph), which is basically sleepily puttering around a house in slippers compared to US 708.

So how did it become so fast?

Dan Meth / BuzzFeed

Well, it's suspected to have been ejected from a type of supernova, or when a star gains too much matter and explodes. In this particular case, US 708 had a binary star buddy, and they orbited one another.

That's where things got a little frayed between the two: Helium-rich US 708 is theorized to have transferred its gas to its companion, which burst into a supernova that shot US 708 across the galaxy, according to a release.

US 708's origin is different from its unbound comrades too: HSVs are believed to be catapulted when a massive black hole consumes one star from a duo and ejects its buddy. But US 708's velocity and trajectory point to a heated binary dispute without the black hole instigator.

Here's a short video that helps visualize the ejection.

View this video on YouTube

Sayonara, gravity!

Science Writer

Contact Kasia Galazka at

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Contact Dan Meth at

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