According to a new analysis of a type of galaxy known as a blazar, the best explanation for unusual changes in their glow is a pair of supermassive black holes locked in a decaying orbit.
A new method, the result of decades of research, has allowed researchers to suppress vacuum noise and extend the reach of the gravitational wave detectors.
The “quiet” black hole is located just 20 light years from the supermassive four-million-solar-mass black hole lurking at the centre of the Milky Way. In the future, it will fall into the supermassive black hole.
The LIGO and Virgo collaborations have now confidently detected gravitational waves from a total of 10 stellar-mass binary black hole mergers and one merger of neutron stars.
An international team of scientists have detected gravitational waves from the biggest known black-hole collision that formed a new black hole about 80 times larger than the Sun.
This confirms the current understanding of cosmological evolution - that galaxies and their associated black holes merge over time, forming bigger and bigger galaxies and black holes.
The Laser Interferometer Gravitational-wave Observatory (LIGO) has done it again, detecting gravitational waves rippling away from a cosmic collision between a pair of black holes.
Gravitational waves sent out from a pair of colliding black holes have been converted to sound waves, as heard in this animation.