The word quasar is a contraction of the words quasi and stellar, defined as a massive and extremely remote celestial object, emitting exceptionally large amounts of energy, which typically has a starlike image in a telescope. It has been suggested that quasars contain massive black holes and may represent a stage in the evolution of some galaxies.
Quasars are so massive and so filled with energy that they defy description: a quasar can have a trillion times the energy of the sun, more energy than the Milky Way galaxy and all the stars in it. The quasar that appears brightest in the sky is 3C 273 in the constellation of Virgo. It has an average apparent magnitude of 12.8 but it has an absolute magnitude of −26.7. From a distance of about 33 light-years, this object would shine in the sky about as brightly as our sun. This quasar’s luminosity is, therefore, about 2 trillion (2 × 1012) times that of our sun, or about 100 times that of the total light of average giant galaxies like our Milky Way.
Quasar image courtesy John Bahcall (Institute for Advanced Study, Princeton) Mike Disney (University of Wales) and NASA/ESA. Image of APM 08279+5255 courtesy of NASA.
Definition courtesy Oxford Dictionaries. Background courtesy Wikipedia.
(via sagansense)
