quasar

[kwey-zahr, -zer, -sahr, -ser]

noun

Astronomy.

1. one of over a thousand known extragalactic objects, starlike in appearance and having spectra with characteristically large redshifts, that are thought to be the most distant and most luminous objects in the universe.

quasar

/ ˈkweɪzɑː, -sɑː /

noun

1. any of a class of extragalactic objects that emit an immense amount of energy in the form of light, infrared radiation, etc, from a compact source. They are extremely distant and their energy generation is thought to involve a supermassive black hole located in the centre of a galaxy

quasar

1. Short for quasi-stellar radio source. A compact, starlike celestial body with a power output greater than our entire galaxy. Believed to be the oldest and most distant objects ever detected, quasars are billions of light-years from Earth and moving away from us at nearly 80 percent of the speed of light. For this reason, quasars are highly important to astronomers' understanding of the early universe. Little is currently understood about the nature of quasars; one theory suggests that they are produced by giant black holes destroying enormous amounts of matter, causing the subsequent ejection of radiation along their north and south poles. Many astronomers believe that quasars represent an early stage in the evolution of galaxies such as our own.

2. See also blazar Seyfert galaxy

Word History and Origins

Origin of quasar¹

1960–65; quas(i-stell)ar, in quasi-stellar radio source, the first type of quasar discovered

Word History and Origins

Origin of quasar¹

C20: quas ( i-stell ) ar ( object )

Example Sentences

The complex analysis used nearly 6 million galaxies and quasars and lets researchers see up to 11 billion years into the past.

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It's been extremely challenging to separate the light from a quasar's central black hole from the light of the host galaxy's stars.

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At a certain point, light from typical galaxies is too faint, so researchers turn to quasars, extremely distant, bright galactic cores with black holes at their centers.

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As the quasar light passes through intervening clouds of hydrogen gas between galaxies, it creates a series of spectral absorption lines known as a Lyman-alpha forest.

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Called quasars, the gas-gobbling black holes are, ironically, some of the universe's brightest objects.

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