pulsar

noun

pul·​sar ˈpəl-ˌsär 

: a celestial source of pulsating electromagnetic radiation (such as radio waves) characterized by a short relatively constant interval (such as .033 second) between pulses that is held to be a rotating neutron star

Examples of pulsar in a Sentence

Recent Examples on the Web

Radio signals from space are not an uncommon occurrence; in fact, telescopes pick up signals all the time coming from pulsars, black holes, massive galaxies, stars and various other cosmic phenomena. —Maria Azzurra Volpe, MSNBC Newsweek, 24 June 2025

Overlaying Chandra's X-ray data (shown in bright blue) with the radio data reveals the likely cause of the fracture to be an impact from a pulsar, a rapidly spinning neutron star that sends out pulses of radiation at regular intervals. —Stefanie Waldek, Space.com, 7 May 2025

Data from those dishes will be combined to study a range of targets, including pulsars and radio emissions from hydrogen that sits relatively close to our own Milky Way galaxy. —IEEE Spectrum, 28 Nov. 2017

The simulation also predicts the possible formation of a rare, hypothetical object known as a black hole pulsar. —Sharmila Kuthunur, Space.com, 5 June 2025

Word History

Etymology

puls(ating) + -ar (in quasar)

Note: The coinage was apparently made by the astronomers Jocelyn Bell Burnell (born 1943 in Northern Ireland) and Antony Hewish (born 1924 in England), who discovered the objects in November, 1967. The Oxford English Dictionary, 3rd edition, cites the following from the Daily Telegraph (March 5, 1968, p. 21): "The name Pulsar (Pulsating Star) is likely to be given to it … Dr. A. Hewish … told me yesterday: '…I am sure that today every radio telescope is looking at the Pulsars.'" The word pulsar was not used in the first formal report of the discovery (A. Hewish, S.J. Bell, et al., "Observation of a Rapidly Pulsating Radio Source," Nature, vol. 217, February 24, 1968, pp. 709-13).

First Known Use

1968, in the meaning defined above