Quasar

:This article is about quasars as they relate to astronomy. See Q-Zar for the lasertag system and Quasar (comics) for the comic book character.

Related Topics:
Q-Zar - Lasertag - Quasar (comics)

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A quasar (contraction of QUASi-stellAR radio sources) is an astronomical object that looks like a star in optical telescopes (i.e. it is a point source), and has a very high redshift. The general consensus is that this high redshift is cosmological, the result of Hubble's law, which implies that quasars must be very distant and must emit more energy than dozens of normal galaxies.

Related Topics:
Astronomical - Object - Star - Telescopes - Redshift - Hubble's law - Galaxies

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Some quasars display rapid changes in luminosity, which implies that they are small (an object cannot change faster than the time it takes light to travel from one end to the other; but see J1819+3845 for another explanation). The highest redshift currently known for a quasar is 6.4 http://www.sdss.org/news/releases/20030109.quasar.html.

Related Topics:
Luminosity - J1819+3845 - Redshift

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