Gravitational ripples from neutron star falling into black hole picked up by LIGO

On 1 April 2019, the LIGO (Laser Interferometer Gravitational-wave Observatory) and VIRGO observatories were switched on after being offline for several months to upgrade their sensitivity to gravitational waves — tiny ripples in the fabric of spacetime that are rare and very hard to detect. Today, gravitational wave detectors like LIGO and VIRGO can observe larger expanses of the universe than before and are always on the lookout for massive, energy-intense collisions of black holes and neutron stars.  LIGO is made up of twin detectors, one based in Washington, and another in Louisiana. VIRGO is the European counterpart of the observatory based in Italy. On 25 April 2019, they heard gravitational waves from a cosmic crash between two neutron stars 500 million light years away. These stars are small and dense and come to existent after stars have exploded to form supernovas. When the two neutron stars collided, they emitted a flash that was visible from Earth for only two seconds. The gravitational waves from the incident lasted for 100 seconds. [caption id=“attachment_6577631” align=“alignnone” width=“1280”] An artist’s illustration of two colliding neutron stars. Image credit: NASA[/caption] On 26 April 2019, the network found another set of waves — a “ collision of a neutron star and black hole, an event never before witnessed.” It took place around 1.2 billion light-years away. “We’re especially curious about the 26 April candidate,” Patrick Brady, spokesperson for the LIGO Scientific Collaboration, said in a statement. Unfortunately, the signal is rather weak. It’s like listening to somebody whisper a word in a busy café; it can be difficult to make out the word or even to be sure that the person whispered at all. It will take some time to reach a conclusion about this candidate."

The LIGO-Virgo collaboration has opened up the universe to the world’s future scientists, according to France Cordova, Director of the National Science Foundation.