Black hole wakes up after 27 years
EarthSky
In the binary system V404 Cygni, a stream of gas from a star much like the sun flows toward a 10 solar mass black hole. Instead of spiraling toward the black hole, the gas accumulates in an accretion disk around it. Every couple of decades, the disk switches into a state that sends the gas rushing inward, starting a new outburst.
On June 15, just before 2:32 p.m. EDT, a NASA satellite detected a rising tide of high-energy X-rays from the constellation Cygnus. About 10 minutes later, a Japanese experiment on the International Space Station (ISS) also picked up the flare.
The outburst came from V404 Cygni, a binary system located about 8,000 light-years away that contains a black hole. Every couple of decades the black hole fires up in an outburst of high-energy light, becoming an X-ray nova. Until now, it had been slumbering since 1989.
An X-ray nova is a bright, short-lived X-ray source that reaches peak intensity in a few days and then fades out over a period of weeks or months. The outburst occurs when stored gas abruptly rushes toward a neutron star or black hole. By studying the patterns of the X-rays produced, astronomers can determine the kind of object at the heart of the eruption.
. ...
Astronomers classify this type of system as a low-mass X-ray binary. In V404 Cygni, a star slightly smaller than the sun orbits a black hole 10 times its mass in only 6.5 days. The close orbit and strong gravity of the black hole produce tidal forces that pull a stream of gas from its partner. The gas travels to a storage disk around the black hole and heats up to millions of degrees, producing a steady stream of X-rays as it falls inward.
More
http://earthsky.org/space/black-hole-wakes-up-after-27-years?utm_source=EarthSky+News&utm_campaign=9fdf3278aa-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-9fdf3278aa-393525109
= new reply since forum marked as read
We are incredibly fortunate to live in a time when we can see this kind of thing, and study it.
Thanks for posting! I REALLY enjoy your posts in the Science group! 
Really cool stuff.
