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AsteriaStar
Astrophysical object

Active Galactic Nucleus

Cosmology & UniverseEstablished Science

Definition

A galaxy centre made unusually luminous by matter accreting onto a supermassive black hole.

Scientific overview

Active galactic nuclei (AGN) span quasars, blazars, and Seyfert galaxies — all powered by a central supermassive black hole. Unified models explain their variety largely by viewing angle and accretion rate.

Rests on

Knowledge connections

Sources & references

The primary and reference sources this topic draws on.

  • NASANational Aeronautics and Space Administration

    Mission data, planetary science, space telescopes, and public-domain imagery.

    Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.

  • ESOEuropean Southern Observatory

    Southern-hemisphere observatory data and imagery (VLT, ALMA partner).