bla·​zar ˈblā-ˌzär How to pronounce blazar (audio)
plural blazars
: a region at the center of a galaxy that emits extremely powerful jets of radiation in the direction of the Earth
Estimated to weigh as much as 10 billion suns and residing 12.5 billion light-years from Earth, the black hole powers the oldest known blazar, a rare class of quasar in which a jet of particles and light points toward Earth. Many blazars also generate high-energy radiation, but X rays and gamma rays from the newfound blazar would have special significance. Such energetic emissions would provide a novel searchlight on the early universe, says Roger W. Romani of Stanford University in Palo Alto, Calif.Ron Cowen, Science News, 3 July 2004
These blazars are a form of active galactic nuclei, objects that researchers know are prolific producers of radiation at other wavelengths.Scott Wakely, Astronomy, September 2006
Active galaxies called blazars make up nearly half of the point sources Fermi detected during its first year. Astronomers think each blazar—like its better-known cousin, the quasar —harbors a well-fed black hole that may weigh a billion solar masses or more. As matter falls into this monster, the blazar emits oppositely directed jets of particles traveling near the speed of light. In the case of blazars, the most luminous class of active galaxy, astronomers suspect we're looking right down one of the jets, whereas we view quasars and other active-galaxy types at larger angles.Francis Reddy, Astronomy, March 2010

Word History


bl (lacertae object) + (qu)asar (respelled after blaze entry 2)

Note: In the article "Optical and infrared polarization of active extragalactic objects," by J.R.P. Angel and H.S. Stockman, Annual Review of Astronomy and Astrophysics, vol. 18 (1980), pp. 321-61, the word is attributed to the Columbia University physicist Edward A. Spiegel: "In a memorable banquet speech at the Pittsburgh meeting on BL Lac objects (the only words spoken not faithfully reported in the proceedings) Ed Spiegel suggested the name 'blazar' for this class of object. A combination of B L Lac object and quasar, with a strong feeling of the characteristic violent optical flaring, blazar seems an excellent name, one which we will adopt throughout the review." The proceedings of the conference in question were published as Pittsburgh Conference on BL LAC Objects, held at the University of Pittsburgh, April 24-26, 1978, edited by Arthur M. Wolfe (University of Pittsburgh, 1978).

First Known Use

1980, in the meaning defined above

Time Traveler
The first known use of blazar was in 1980

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

  • More than 250,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

Dictionary Entries Near blazar

Cite this Entry

“Blazar.” Dictionary, Merriam-Webster, Accessed 22 May. 2024.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!