The terrible tidal forces near a supermassive black hole at the center of another galaxy was recently observed to have ripped apart a nearby star that fell in too close... Astronomers noted that the remnants of the torn-apart star were emitting bright X-rays, and...
"Now researchers at MIT and elsewhere have pored through data from multiple telescopes' observations of the event, and discovered a curiously intense, stable, and periodic pulse, or signal, of X-rays, across all datasets. The signal appears to emanate from an area very close to the black hole's event horizon...The signal appears to periodically brighten and fade every 131 seconds...The researchers believe that whatever is emitting the periodic signal must be orbiting the black hole, just outside the event horizon...Given the signal's stable proximity to the black hole and the black hole's mass, which researchers previously estimated to be about 1 million times that of the sun, the team has calculated that the black hole is spinning at about 50 percent the speed of light."
(Fast enough to make you dizzy...)
It's kind of amazing.
https://www.eurekalert.org/pub_releases/...010319.php
http://science.sciencemag.org/content/ea...ce.aar7480
Apparently supermassive black holes are usually rather passive and quiet as far as X-ray emissions go. But they perk up temporarily when they eat stars. The partially chewed star remnants get very bright for a while as they whirl around the black hole in its accretion disk. Now it's been shown that data on the black hole's rate of spin can be extracted from the periodicity of the emissions and the black hole's mass. (The mass determines the size of the event horizon, hence the minimum size of the orbit.) Spin data is of major interest to astrophysicists and has been something that's been very hard to determine up to now. And the really fast relativistic spin speeds makes it even more interesting...
"Now researchers at MIT and elsewhere have pored through data from multiple telescopes' observations of the event, and discovered a curiously intense, stable, and periodic pulse, or signal, of X-rays, across all datasets. The signal appears to emanate from an area very close to the black hole's event horizon...The signal appears to periodically brighten and fade every 131 seconds...The researchers believe that whatever is emitting the periodic signal must be orbiting the black hole, just outside the event horizon...Given the signal's stable proximity to the black hole and the black hole's mass, which researchers previously estimated to be about 1 million times that of the sun, the team has calculated that the black hole is spinning at about 50 percent the speed of light."
(Fast enough to make you dizzy...)
It's kind of amazing.
https://www.eurekalert.org/pub_releases/...010319.php
http://science.sciencemag.org/content/ea...ce.aar7480
Apparently supermassive black holes are usually rather passive and quiet as far as X-ray emissions go. But they perk up temporarily when they eat stars. The partially chewed star remnants get very bright for a while as they whirl around the black hole in its accretion disk. Now it's been shown that data on the black hole's rate of spin can be extracted from the periodicity of the emissions and the black hole's mass. (The mass determines the size of the event horizon, hence the minimum size of the orbit.) Spin data is of major interest to astrophysicists and has been something that's been very hard to determine up to now. And the really fast relativistic spin speeds makes it even more interesting...