by Chelsea Gohd
An artist's impression of the star
being ejected by the Milky Way
supermassive black hole, Sagittarius
Image credit: James Josephides
Swinburne Astronomy Productions
"It is a visitor
from a strange land."
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
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.
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.
"This is super
exciting, as we have long suspected that black holes can eject
stars with very high velocities.
However, we never had an
unambiguous association of such a fast star with the galactic
center," Koposov said in the 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
The discovery was made as part of the
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
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
of the star S5-HVS1 in the night sky.
The star is rocketing
from the center of our galaxy.
(Image credit: Sergey Koposov)
"This is the
first clear demonstration of the Hills Mechanism in action,"
Ting Li, a fellow at the Carnegie Observatories and Princeton
University who led the S5 collaboration, said in the statement.
star is really amazing as we know it must have formed in the
galactic center, a place very different to our local
It is a visitor from a strange land."
"While the main
science goal of S5 is to probe the stellar streams - disrupting
dwarf galaxies and globular clusters - we dedicated spare
resources of the instrument to searching for interesting targets
in the Milky Way, and voila, we found something amazing for
With our future
observations, hopefully we will find even more!" Kyler Kuehn,
deputy director of technology at the Lowell Observatory who is
part of the S5 executive committee, added in the statement.
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.