GERMAN ASTRONOMERS SAY MASSIVE BLACK HOLE DISCOVERED AT CENTER OF OUR GALAXY

Wed, 2 Oct 1996
Source: Nando Times / Reuter
LONDON (Oct 2, 1996 6:54 p.m. EDT) - German astronomers said on Wednesday they had all but proved there was a massive black hole at the centre of our galaxy, the Milky Way.

Reinhard Genzel of the Max-Planck Institute for Extra-Terrestrial Physics, near Munich, said he remained cautious about claiming absolute proof that the black hole existed.

But "it was caution backed up by the best evidence that has yet existed," he told Reuters.

Evidence for a massive black hole -- an object that sucks matter towards it and is so dense that not even light can escape -- has been accumulating for the past 20 years.

The only means of detecting a black hole is by observing its gravitational effects on other objects. Line-of-sight velocity of stars orbiting the galactic centre had suggested the presence of a black hole but proof was missing. Since 1992, scientists at the Max-Planck Institute have measured the "proper" motions -- at right angles to line-of-sight velocities -- of 39 stars in the Milky Way, they reported in Nature magazine.

Their observations backed up the assumption that the stars moved in circular orbits around a large central mass with gravitational pull. If orbits had been irregular, it would have shown the central mass was much smaller.

"The fact that we were able to come so close to the central object and to test the velocities of the stars -- that's what makes the measurements unique," Genzel said.

The central dark mass was about 2.5 million times greater than the sun, the research showed.

"Why do I hesitate (in claiming absolute proof)? Before we go too far, we will give the information to colleagues around the world and they will test it," he said.

"Our colleagues will take it as a very interesting new step but it has to be confirmed. By early next year, if they don't find any problems, then it will be a definite."

In a commentary published in Nature, Mark Morris from the University of California said the German findings "show with little ambiguity that about 2.5 million solar masses of dark matter lurks within a relatively tiny region at the centre."

The probable black hole is situated very close to a bright, as yet unresolved, radio source called Sagittarius A+. The German measurements are consistent with the possibility that all the dark mass is in Sagittarius A+ and fulfils the theory about how hot gas sucked into a black hole would behave, Morris said.

Back to UFO news update menu

All rights reserved to WUFOC and NÄRKONTAKT. If you reprint or quote any part of the content, you must give credit to: WUFOC, the free UFO-alternative on the Internet, http://www.wufoc.com