Reporting at LiveScience.
As humankind's ancestors were learning to walk upright, a star was launched out of the supermassive black hole at the center of our galaxy at a staggering 3.7 million mph (6 million km/h).
Five million years after this dramatic ejection, a group of researchers, led by Sergey Koposov of Carnegie Mellon University's McWilliams Center for Cosmology, has spotted the star, known as S5-HVS1, in the Crane-shaped constellation Grus. The star was spotted traveling relatively close to Earth (29,000 light-years away) at unprecedented, searing speeds — about 10 times faster than most stars in our galaxy.
"The velocity of the discovered star is so high that it will inevitably leave the galaxy and never return," Douglas Boubert, a researcher at the University of Oxford and a co-author on the study, said in a statement.
[...] The star was discovered with observations from the Anglo-Australian Telescope (AAT), a 12.8-foot (3.9-meter) telescope, and the European Space Agency's Gaia satellite. The discovery was made as part of the Southern Stellar Stream Spectroscopic Survey (S5), a collaboration of astronomers from Chile, the U.S., the U.K. and Australia.
Now that the star has been spotted, researchers could track the star back to Sagittarius A*, the black hole at the center of the Milky Way. It also serves as an incredible example of the Hills Mechanism, proposed by astronomer Jack Hills 30 years ago, in which stars are ejected from the centers of galaxies at high speeds after an interaction between a binary-star system and the black hole at the center of the galaxy.
[...] This discovery was published in a study on Nov. 4[$] in the journal the Monthly Notices of the Royal Astronomical Society.
(Score: 3, Informative) by corey on Friday November 15 2019, @10:40PM (3 children)
But everything's relative. I assume that velocity is relative to Sag A*. What is our velocity rotating about Sag A*? Our or Milky Way moving through space.
Quick calc, it's going at 0.0055c. Doesn't sound that fast now, but would be interesting to be in an orbit around that star.
(Score: 2) by JoeMerchant on Friday November 15 2019, @10:49PM (2 children)
0.0055C relative to what? ;-)
The article I read said it was moving about 10x faster than normal stars, and was on an escape trajectory from the Milky Way... fast, but hardly mind blowing, particularly if you've ever run a black hole orbital sim... Maybe impressive that it held together while achieving that speed. I bet there's more than one physics lab that has run simulations of just how fast a star can get going in a black hole slingshot without permanently ripping apart - I'm pretty sure that the bigger holes like Sag-A make that easier...
🌻🌻 [google.com]
(Score: 2) by aristarchus on Saturday November 16 2019, @12:04AM
See the original submission, per usual.
(Score: 1) by khallow on Saturday November 16 2019, @05:16PM
Permanently ripped apart doesn't mean much for balls of gas. One likely outcome is multiple stars ejected from the galactic core.