A neutron star has produced gravitational waves after colliding with an unknown object – it could be the smallest black hole or biggest neutron star ever found
Source:
https://www.newscientist.com/article/2229190-gravitational-wave-mystery-could-be-a-sign-of-a-new-kind-of-black-hole/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home