Your Web News in One Place

Help Webnuz

Referal links:

Sign up for GreenGeeks web hosting
July 27, 2018 01:00 pm

Star's Black Hole Encounter Puts Einstein's Theory of Gravity To the Test

An anonymous reader quotes a report from Science Magazine: For more than 20 years, a team of astronomers has tracked a single star whipping around the supermassive black hole at the center of our galaxy at up to 25 million kilometers per hour, or 3% of the speed of light. Now, the team says the close encounter has put Albert Einstein's theory of gravity to its most rigorous test yet for massive objects, with the light from the star stretched in a way not prescribed by Newtonian gravity. In a study announced today, the team says it has detected a distinctive indicator of Einstein's general theory of relativity called "gravitational redshift," in which the star's light loses energy because of the black hole's intense gravity. The star, called S2, is unremarkable apart from a highly elliptical orbit that takes it within 20 billion kilometers, or 17 light-hours, of the Milky Way's central black hole -- closer than any other known star. A team led by Reinhard Genzel at the Max Planck Institute for Extraterrestrial Physics (MPE) in Garching, Germany, has been tracking S2 since the 1990s, first with the European Southern Observatory's (ESO's) 3.6-meter New Technology Telescope in Chile's Atacama Desert and later with ESO's Very Large Telescope (VLT), made up of four 8-meter instruments. Ghez's team at UCLA also began to observe the star around the same time with the twin 10-meter Keck telescopes in Hawaii. In a paper published today in Astronomy & Astrophysics, Genzel's group reports seeing the combined action of the relativistic effects, with the black hole's gravity redshifting S2's radial velocity by 200 kilometers per second, a small fraction of its overall speed. The results match closely with the predictions of relativity and are inconsistent with Newtonian gravity.

Read more of this story at Slashdot.


Original Link: http://rss.slashdot.org/~r/Slashdot/slashdot/~3/7h27nFEhmn4/stars-black-hole-encounter-puts-einsteins-theory-of-gravity-to-the-test

Share this article:    Share on Facebook
View Full Article

Slashdot

Slashdot was originally created in September of 1997 by Rob "CmdrTaco" Malda. Today it is owned by Geeknet, Inc..

More About this Source Visit Slashdot