Chad Hanna was enjoying a quiet Christmas night with family in rural western Pennsylvania when he got the text message. He sprang for his phone, surprising his in-laws. Then he grabbed his laptop and flew up the stairs to an empty bedroom.
The cosmos had quietly gifted scientists with a second gravitational wave, dubbed GW151226, from two black holes that collided 1.4 billion light-years away. The signal from those black holes — one 14 solar masses and the other eight — showed the final dozens of death spirals before the pair smashed together with such intensity that a mass equal to our sun radiated out as gravitational waves. That announcement came Wednesday at theAmerican Astronomical Society meeting in San Diego.
Keeping the Secret
At the time of the second detection, scientists working on theLaser Interferometer Gravitational-wave Observatory (LIGO) were already confident they had the historic first signal in the bag. But that knowledge remained a closely guarded secret, even as rumors trickled out to media outlets around the world.
So Hanna couldn’t explain his strange behavior.
“My family had no idea what was going on,” says Hanna, a LIGO scientist from Pennsylvania State University. “In fact, they didn’t really know that much about what I do for a living. Until recently it was pretty esoteric and not something that the public at large had any experience with.”
