quasi-stellar object

astronomy

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July 19, 2026

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Quasars, or quasi-stellar objects, are extremely luminous astronomical objects found at the centers of some galaxies. Despite their small size, comparable to our solar system, they emit up to 100 times more radiation than an entire galaxy. This immense energy output is generated as matter spirals into a supermassive black hole.12

Originally discovered as powerful radio sources that appeared star-like, their immense redshift indicated they were incredibly distant and luminous. Quasars are now understood as extreme examples of active galactic nuclei (AGN), where the central black hole's accretion process outshines the host galaxy. They were more common in the early universe, with their activity likely triggered by galactic mergers.123

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quasar
Discovery of quasars
…luminosity, became known as “quasi-stellar objects” or simply QSOs. Since the early 1980s most astronomers have regarded QSOs as the high-luminosity variety of an even larger population of “active galactic nuclei,” or AGNs. (The lower-luminosity AGNs are known as “Seyfert galaxies,” named after the American astronomer Carl K. Seyfert,…
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…luminosity, became known as “quasi-stellar objects” or simply QSOs. Since the early 1980s most astronomers have regarded QSOs as the high-luminosity variety of an even larger population of “active galactic nuclei,” or AGNs. (The lower-luminosity AGNs are known as “Seyfert galaxies,” named after the American astronomer Carl K. Seyfert,…
Read More