Definitions for quasar
ˈkweɪ zɑr, -zər, -sɑr, -sərquasar

Princeton's WordNetRate this definition:5.0 / 1 vote

1. quasar, quasi-stellar radio sourcenoun

   a starlike object that may send out radio waves and other forms of energy; many have large red shifts

WiktionaryRate this definition:4.0 / 1 vote

1. quasarnoun

   An extragalactic object, starlike in appearance, that is among the most luminous and thought to be the most distant objects in the universe.

2. Etymology: From quasi-stellar radio source.

WikipediaRate this definition:0.0 / 0 votes

1. Quasar

   A quasar is an extremely luminous active galactic nucleus (AGN). It is pronounced KWAY-zar, and sometimes known as a quasi-stellar object, abbreviated QSO. This emission from an AGN is powered by a supermassive black hole with a mass ranging from millions to tens of billions of solar masses, surrounded by a gaseous accretion disc. Gas in the disc falling towards the black hole heats up because of friction and releases energy in the form of electromagnetic radiation. The radiant energy of quasars is enormous; the most powerful quasars have luminosities thousands of times greater than that of a galaxy such as the Milky Way. Usually, quasars are categorized as a subclass of the more general category of AGN. The redshifts of quasars are of cosmological origin.The term quasar originated as a contraction of "quasi-stellar [star-like] radio source"—because quasars were first identified during the 1950s as sources of radio-wave emission of unknown physical origin—and when identified in photographic images at visible wavelengths, they resembled faint, star-like points of light. High-resolution images of quasars, particularly from the Hubble Space Telescope, have demonstrated that quasars occur in the centers of galaxies, and that some host galaxies are strongly interacting or merging galaxies. As with other categories of AGN, the observed properties of a quasar depend on many factors, including the mass of the black hole, the rate of gas accretion, the orientation of the accretion disc relative to the observer, the presence or absence of a jet, and the degree of obscuration by gas and dust within the host galaxy. More than a million quasars have been found, with the nearest known being about 600 million light-years away from Earth. The record for the most distant known quasar continues to change. In 2017, the quasar ULAS J1342+0928 was detected at redshift z = 7.54. Light observed from this 800-million-solar-mass quasar was emitted when the universe was only 690 million years old. In 2020, the quasar Pōniuāʻena was detected from a time only 700 million years after the Big Bang, and with an estimated mass of 1.5 billion times the mass of the Sun. In early 2021, the quasar J0313–1806, with a 1.6-billion-solar-mass black hole, was reported at z = 7.64, 670 million years after the Big Bang.Quasar discovery surveys have demonstrated that quasar activity was more common in the distant past; the peak epoch was approximately 10 billion years ago. Concentrations of multiple, gravitationally attracted quasars are known as large quasar groups and constitute some of the largest known structures in the universe.

ChatGPTRate this definition:0.0 / 0 votes

1. quasar

   A quasar, short for 'quasi-stellar radio source', is an extremely bright and distant celestial object, emitting exceptionally large amounts of energy. They are thought to be powered by supermassive black holes at the centre of certain galaxies. They are among the brightest and most distant objects in the known universe.

WikidataRate this definition:0.0 / 0 votes

1. Quasar

   A quasi-stellar radio source is a very energetic and distant active galactic nucleus. Quasars are extremely luminous and were first identified as being high redshift sources of electromagnetic energy, including radio waves and visible light, that were point-like, similar to stars, rather than extended sources similar to galaxies. While the nature of these objects was controversial until as recently as the early 1980s, there is now a scientific consensus that a quasar is a compact region in the center of a massive galaxy, that surrounds its central supermassive black hole. Its size is 10–10,000 times the Schwarzschild radius of the black hole. The quasar is powered by an accretion disc around the black hole.

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1. • Celestial Body

How to pronounce quasar?

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How to say quasar in sign language?

Numerology

1. Chaldean Numerology

   The numerical value of quasar in Chaldean Numerology is: 5

2. Pythagorean Numerology

   The numerical value of quasar in Pythagorean Numerology is: 5

Examples of quasar in a Sentence

1. Chris Carilli:

   This quasar’s brightness and its great distance make it a unique tool to study the conditions and processes that prevailed in the first galaxies in the Universe, we look forward to unraveling more of its mysteries.

2. Fuyun Bian:

   However this black hole at the center of the quasar gained enormous mass in a short period of time.

3. Chris Carilli:

   We are seeing P352-15 as it was when the Universe was less than a billion years old, or only about 7 percent of its current age, this is near the end of a period when the first stars and galaxies were re-ionizing the neutral hydrogen atoms that pervaded intergalactic space. 'SUPERSTAR' ETA CARINAE ACTS LIKE A GINORMOUS COSMIC-RAY GUN, BUT WHY? Carilli added: Further observations may allow us to use this quasar as a background ‘lamp’ to measure the amount of neutral hydrogen remaining at that time.

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References

1. ^ Princeton's WordNet
   http://wordnetweb.princeton.edu/perl/webwn?s=quasar
2. ^ Wiktionary
   https://en.wiktionary.org/wiki/Quasar
3. ^ Wikipedia
   https://en.wikipedia.org/wiki/Quasar
4. ^ ChatGPT
   https://chat.openai.com
5. ^ Wikidata
   https://www.wikidata.org/w/index.php?search=quasar