In a similar way, astrophysicists like us who study supermassive black holes expect to find binary systems – two supermassive black holes orbiting each other – at the hearts of some galaxies.

If galaxies weren't packed with invisible dark matter ... "Because of this spin down, we were initially forced to use only pulsars in binary systems to calculate accelerations because the orbits ...

Here’s how it works. Astronomers have discovered something surprising about the universe's smallest and faintest class of galaxies: Ultra-Diffuse Galaxies (UDGs). A research team studying these ...