Quasars are perhaps the best-known kinds of active galactic nuclei (AGN), galaxies whose central supermassive black holes are luminous, sometimes brighter than the rest of the galaxy. In ...

Sunspots were first seen by Galileo, and in the eighteenth century Rudolf Wolf concluded from his study of previous observations that there was a roughly eleven-year solar cycle of activi...

Ninety years after Edwin Hubble discovered the systematic motions of galaxies and George Lemaitre explained them as cosmic expansion from a point using Einstein’s equations of relativity,...

The most luminous galaxies in the universe can be over a thousand times brighter than our Milky Way. They are not particularly bright in the optical, however, because most of their radiat...

Planets are formed from the disk of gas and dust around a star, but the mechanisms for doing so are imperfectly understood.  Gas is the key driver in the dynamical evolution of plane...

Artificial intelligence is classifying real supernova explosions without the traditional use of spectra, thanks to a team of astronomers at the Center for Astrophysics | Harvard & Smi...

A meteor is a rocky or metallic body that enters the Earth’s atmosphere (or the atmosphere of another planet) from space at high speed and burns up; meteors that mostly survive the trip a...

Seyfert galaxies are distinguished by their bright nuclei and radiation from highly ionized atoms. Seyferts look much like quasars, but unlike point-like quasars the Seyfert host galaxies...

Proxima Centauri is the closest star to the Sun, and its planet, Proxima Cen b ("Proxima b"), lies in its habitable zone (the distance range within which surface water can be liquid), mak...

Nancy Brickhouse of The Center for Astrophysics | Harvard & Smithsonian has been named a Fellow of the American Association for the Advancement of Science (AAAS). Election as a AAAS F...