In the last few years, astronomers have identified 10 “hypervelocity” stars, which race away from the Milky Way at 10 times the speed of normal stars. Nine of these burning bullets are believed to have originated in our own galaxy. What about #10?
Yesterday, astronomers from the Carnegie Institution and Queen’s University Belfast announced that the stellar stranger isn’t from around here. The star is believed to be only about 35 million years old, but it’s about 100 million years away from the center of our galaxy. (They’re calling this the “paradox of youth.”) They estimate that the star is moving at about 1.6 million miles per hour.
How to explain the conflict between its time and position? The stargazers came up with two theories and finally settled on this one: they believe the young star “recently” escaped from the Large Magellanic Cloud (one of our nearest neighboring galaxies).
“Escaped” is probably the wrong word here—“violently expelled” is more like it.
The astronomers suspect that the star, HE 0437-5439, was orbiting another star as part of a binary system. When the two stars dosey-doed a little too close to a black hole, however, the black hole swallowed up the partner and sent the HE 0437-5439 shooting out of the neighborhood, towards ours.
But if the astronomers are right, then their work points to an even more exciting conclusion: There’s a shady, unidentified black hole at the center of the Large Magellanic Cloud.
From the Carnegie Press Release:
“This is the first observational clue that a massive black hole exists somewhere in the LMC. We look forward to finding out where this black hole might be,” concluded Bonanos.
The study is scheduled to be published in a forthcoming Astrophysical Journal
Last summer, a separate team of astronomers postulated that the high speeds of hypervelocity stars might be due to a second black hole at the center of the Milky Way.
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