Date:24 August 2017
Rumours are swirling that the LIGO observatory has finally spotted a gravitational wave from colliding neutron stars.
By Avery Thompson
Last year, a group of astronomers made history when they discovered gravitational waves for the first time, using the highly sensitive LIGO observatory. These gravitational waves were ripples in the fabric of spacetime caused by two colliding black holes many lightyears away. Over the next year, the astronomers made two more detections of gravitational waves, launching a new branch of astronomy.
But all three of these detections have been of colliding black holes, which is exciting but somewhat limiting for gravitational wave astronomy. It’s like if our telescopes could only see one specific type of star. Fortunately, LIGO might be about to diversify, if recent rumours are correct. New Scientist is reporting that LIGO may have spotted gravitational waves from a brand new kind of source: neutron stars.
Neutron stars are similar to black holes in that they’re both formed from the remnants of exploding stars, but neutron stars are smaller and less massive. Instead of collapsing into an infinitely small point, neutron stars instead collapse a sun-sized star into a sphere only a few miles wide. Neutron stars are some of the densest objects in the universe.
Colliding neutron stars give out similar signals as colliding black holes, but they’re smaller and harder to find. LIGO has long been searching for signals from neutron stars, but until now they’ve been unsuccessful.
According to New Scientist, there’s a good chance LIGO is about to announce the discovery of gravitational waves from neutron stars by the end of the week. LIGO itself is neither confirming or denying any discovery, but astronomer J. Craig Wheeler of the University of Texas at Austin posted a tweet hinting at a neutron star discovery.
Simultaneously, the Hubble telescope has been spending time observing a pair of neutron stars in the galaxy NGC 4993, about 130 million light years away. If LIGO did detect a collision, it would explain why valuable telescope time was being used to watch an otherwise unremarkable set of stars.
Either way, we won’t know for sure until Friday. LIGO spokesperson David Shoemaker told New Scientist, “A very exciting O2 Observing run is drawing to a close August 25. We look forward to posting a top-level update at that time.” So we’ll just have to wait until then to find out.
Source: New Scientist
From: PM USA