Second Gravitational Wave likely detected

In February, LIGO announced the first detection of gravitational waves, confirming a key prediction of Albert Einstein’s theory of general relativity. That historic wave reached Earth at light speed on September 14, 2015, from a pair of black holes that collided 1.3 billion light-years away.

But LIGO heard another suspect gravitational wave signal that got less attention. Though it wasn’t as strong, it looked promising.

The Other Collision
An analysis of that event, labeled LVT151012, has shown with 90 percent certainty that it also came from a pair of colliding black holes. That’s not sufficient for scientists to deem it a “detection,� but the LIGO team is confident enough that they’re using it to start piecing together a picture of black holes in the universe.

As more detections stream in from LIGO, astronomers can begin to get an idea for the size of most stellar mass black holes. The likely second detection, LVT151012, had black holes of 23 and 13 solar masses — more in line with what astronomers expected to detect.


Prepare for an explosion of gravitational wave detections | Astronomy.com
http://www.astronomy.com/news/2016/0...ave-detections