by Chelsea Gohd
November 12, 2019
from Space Website
An artist's impression of the star S5-HVS1
being ejected by the Milky Way galaxy's
supermassive black hole, Sagittarius A*.
Image credit: James Josephides
Swinburne Astronomy Productions
from a strange land."
As humankind's ancestors were learning to walk upright, a star was launched from 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 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.
The location and direction
of the star S5-HVS1 in the night sky.
The star is rocketing away
from the center of our galaxy.
(Image credit: Sergey Koposov)
This discovery (Discovery of a nearby 1700 km/s star ejected from the Milky Way by Sgr A*) was published in a study on Nov. 4 in the journal the Monthly Notices of the Royal Astronomical Society.