Quasar luminosities can vary considerably over time, depending on their surroundings. Since it is difficult to fuel quasars for many billions of years, after a quasar finishes accreting the …

Jun 3, 2025 · Quasars occur when immense amounts of matter fall into a supermassive black hole, spiraling around it in the form of a disk before entering.

Dec 29, 2025 · Quasar, an astronomical object of very high luminosity found in the centres of some galaxies and powered by gas spiraling at high velocity into an extremely large black hole.

Oct 19, 2023 · Quasars are the remarkably bright cores of active galaxies in the distant universe, they are an extreme form of what astronomers call "active galactic nuclei", or AGN for short. …

Oct 29, 2024 · Learn what a quasar is in astronomy, how it forms, types of quasars, and what they tell us about the early universe.

Quasars are a subclass of active galactic nuclei (AGNs), extremely luminous galactic cores where gas and dust falling into a supermassive black hole emit electromagnetic radiation across the …

Apr 14, 2025 · A quasar is an extremely bright galactic core powered by a supermassive black hole, emitting massive energy as gas spirals inward, outshining entire galaxies.

Oct 22, 2025 · Quasars, short for quasi-stellar radio sources, are extremely bright and distant celestial objects that emit massive amounts of energy. They are considered to be the most …

Mar 16, 1998 · The word 'quasar' is a contraction of 'quasi-stellar radio source'. The first quasars were discovered in the early 1960s, when astronomers measured their very strong radio …

In those cases, astronomers call the AGN a “quasar” or “blazar”. If the jets aren’t pointing toward Earth or the black hole doesn’t produce jets, the AGN might still be bright, but take on a …