active galactic nuclei

An artist's impression of how ULAS J1120+0641, a very distant quasar powered by a black hole with a mass two billion times that of the Sun, may have looked. Credit: ESO/M. Kornmesser, CC BY 4.0

Is the Universe Different In Different Directions?

Physicists Detect Gravitational Waves From Heaviest Black-Hole Merger Yet

Albert Einstein, general theory of relativity, gravitational lensing, Fritz Zwicky, Hubble constant, expansion of the universe, Sjur Refsdal, Orest Chwolson, Arthur Eddington, active galactic nuclei, black hole, Type Ia supernovae, Palomar Transient Factory,

How Astronomers Use Ginormous Natural Lenses to Study Distant Space Explosions

How an Astronomer Is Trying to Solve Mysteries From Far-Off Galaxies