London, Oct. 16 (Reuters): Scientists said today they have discovered at the centre of our galaxy a huge black hole, a mysterious celestial object that sucks in everything around it, including light.
By observing the orbit of a star around the invisible gravitational field, an international team of scientists has eliminated other possibilities of explaining the phenomenon.
“It is a great step forward,” said Dr Reinhard Genzel, a scientist with the Max-Planck Institute for Extraterrestrial Physics near Munich and leader of the team.
“We have been able to exclude some still possible alternative configurations... there is nothing left that one would consider realistic and possible, other than a black hole,” he added.
Astronomers have been gathering information about black holes, which are detected by measuring their effect on nearby stars or the activity around their edges, for more than 20 years.
There has been growing evidence of a massive black hole, more than a million times the mass of the Sun, at the centre of our galaxy and others, but Genzel and his team believe their research is the best proof so far.
“Most astrophysicists would accept that the new data provide compelling evidence that a super-massive black hole exists in the centre of the Milky Way,” said Alvio Renzini, a scientist at the European Southern Observatory in Chile.
Black holes, like the one in the centre of the Milky Way, are thought to be the remains of dead quasars, the powerful, super-bright hearts of galaxies.
First posited by Albert Einstein, black holes have been described as the ultimate victory of gravity because of their ability to suck in stars and other galactic features.
Genzel and his team, whose research is reported in the science journal Nature, zeroed in on the black hole by analysing 10 years of data to observe nearly the entire orbit of a star called S2 around the black hole.
“This is the only case we know of in all astronomy where such a star is so close and we can observe it. Most of the other stars have orbital periods between hundreds and millions of years,” Genzel said.
S2, which is seven times larger than the Sun and must travel at phenomenal speed to avoid being sucked in by the black hole, has an orbit of about 15 years.