Star spewed out by supermassive black hole spotted hurtling through universe at 3.7 million mph

A star has been spotted barrelling through the universe at record-breaking speeds after it was hurled by a supermassive black hole.

The object was thrown out of a black hole at the centre of our galaxy known as Sagittarius A*.

It is moving so fast it will eventually be flung from our galaxy and spend the rest of its life sailing alone through the intergalactic abyss, scientists said.

At speeds of 1,700km per second, it is travelling “10 times faster than most stars in the Milky Way, including our sun,” according to one of the astronomers who made the discovery.

It is the first time a black hole has been recorded ejecting a star at such high speeds.

The runaway star was spotted in the constellation of Grus, also known as the crane, by researchers from Carnegie Mellon University.

They made the finding using a 3.9-metre Anglo-Australian Telescope (AAT) located near Coonabarabran, Australia, according to a study published in the journal Monthly Notices of the Royal Astronomical Society.

“In astronomical terms, the star will be leaving our galaxy fairly soon and it will likely travel through the emptiness of intergalactic space for eternity,” said astronomer Gary Da Costa, of the Australian National University (ANU) in Canberra, one of the study’s authors.

The star, known as S5-HVS1, is the third-fastest star ever measured, trumped only by two which were thrust out by supernovae explosions.

“Excluding these somewhat special cases, this star is far and away the fastest ever spotted,” said co-author Dougal Mackey, also of the ANU College of Science.

The experts believe Sagittarius A* ejected the star with a speed of thousands of kilometres per second about five million years ago.

“This ejection happened at the time when humanity's ancestors were just learning to walk on two feet," explained the study’s lead author Sergey Koposov, of Carnegie Mellon's McWilliams Center for Cosmology.

"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," he added.

After the star exits the Milky Way it will continue its journey through the intergalactic space, eventually ending up as a white dwarf like our sun, the team predict.

The star began as one half of a binary system that ventured too close to the hostile environment of Sagittarius A*, which has a mass equivalent to more than four million suns.

As the twin stars spiralled into the intense gravitational environment around the black hole, the companion star was eaten up, but S5-HVS1 was thrown out at incredible speed via a process known as the Hills Mechanism.

The process was named after the astronomer Jack Hills who proposed the scenario more than 30 years ago.

“This is the first clear demonstration of the Hills Mechanism in action," said Ting Li, another author of the study, from Carnegie Observatories and Princeton University,

"Seeing this star is really amazing as we know it must have formed in the galactic centre, a place very different to our local environment,” she added.

“It is a visitor from a strange land.”