(CNN) For only the second time, astronomers have detected gravitational waves that were created by the violent merger of two neutron stars, according to a new study. But the two neutron stars that collided are more massive than all known binary star pairs. They collided 520 million light-years away, so the gravitational waves are just now reaching us even though they occurred millions of years ago. The first detection of gravitational waves created by a neutron star collision was made in August 2017 . Pairs of neutron stars form when two massive stars in a binary system come to the end of their lives.

Source: CNN January 06, 2020 22:30 UTC