Beyond Black Holes: Could LIGO Have Detected Merging Neutron Stars For The First Time?
“We are present at an incredible time in history: at the birth of the observational science of gravitational wave astronomy. The coming decades will reveal a series of “firsts,” and that should include the first binary neutron star merger, the first pinpointing of a gravitational wave source, and the first correlation between gravitational waves and an electromagnetic signal. If nature is kind to us, and the rumors are true, we may have just unlocked all three.”
It seems like an eternity ago, but it’s been under two years since LIGO first began the science run that would first detect merging black holes. Their latest scientific data run is scheduled to end in just two days, and thus far, they’ve announced a total of three black hole-black hole merger discoveries, along with a fourth probable candidate. Yet thanks to the Twitter account of renowned astrophysicist J. Craig Wheeler, a bit of information has leaked: LIGO may have discovered merging neutron stars for the first time. They’d be approximately ten times lighter than the black holes we’ve witnessed merging, which means the signals are only 10% as strong. In order to get the same amplitude, they’d need to be only 10% as distant, cutting the search volume down to 0.1% the volume. But still, neutron stars may be much more abundant, so we might have a chance. Just yesterday, Hubble observed a galaxy with a binary neutron star inside, just 130 million light years away.