Saturday , September 26 2020

Superfast star found as it departs from the Milky Way at 1,700 km / second | Science


Astronomers have observed a star emerging from the Milky Way at more than 6 million kilometers per hour (3.7 miles per hour), or 1,700 kilometers per second, after meeting the supermassive black hole in the center of the galaxy.

The planet is moving so fast that it will leave the Milky Way for about 100 million years and spend the rest of its life sailing alone in intergalactic space. Although it was predicted 30 years ago that black holes could emit galaxies at phenomenal speeds, such an event was first recorded.

Gary Da Costa, an astronomer and epithet professor at the Australian National University (ANU) in Canberra, said: "We watched this star's journey back to the center of our galaxy, which is pretty exciting."

Da Costa and his colleagues concluded that 5 million years ago, the star was part of a binary star system that landed extremely close to Sagittarius A *, the location of the central black hole of the Milky Way, which has a mass equivalent to more than 4 million suns. .

As the twin stars spiraled inward, at some point the two of them became a binary partnership with the black hole that would eventually end up mocking and disappearing into oblivion. The dynamics of this interaction resulted in the original partner being ejected at extremely high speed.

The process is known as the Hills mechanism, after astronomer Jack Hills proposed the script more than 30 years ago.

"This star travels at record speeds, 10 times faster than most stars on the Milky Way, including our sun," said Da Costa. "In astronomical terms, the star will leave our galaxy pretty soon and will probably travel through the emptiness of the intergalactic space for eternity."

The star, known as the S5-HVS1, is the third fastest star ever measured. The other two were those that were increased at high speeds in supernova explosions.

"Excluding these somewhat special cases, this star is by far the fastest ever observed," said Dougal McKay, also co-author of the ANU College of Science.

The team discovered the star using a 3.9-foot Anglo-Australian telescope at the ANU Siding Spring Observatory. The team looked at star-studded streams in the Milky Way's eye that reach the galactic disc, but had the additional capacity to look at other stars, and through these observations made the S5-HVS1's main discovery.

Once the star exits the Milky Way, it will continue its journey through the intergalactic space. "Will continue and eventually end up as a white dwarf like our sun; there just won't be any neighbors, "said Da Costa.

The study results are published in the Royal Astronomical Society Monthly Reports.

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