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

Luckily for scientists, this rapid spin and its precise frequency make pulsars excellent timing mechanisms. —Robert Lea, Space.com, 28 Feb. 2025

Among other things, it is expected to be able to hunt for the universe’s first stars, search for signals from an extraterrestrial intelligence, and enable the detection of new pulsars—the spinning remnants of dead stars—in our galaxy and others. —IEEE Spectrum, 26 Sep. 2016

While there are some natural short-duration signals, namely fast radio bursts and pulsars, these have other characteristics that single them out. —IEEE Spectrum, 28 Jan. 2021

These effects [known as magnetic braking] lead to the pulsar spinning more slowly as time goes on. —Robert Lea, Space.com, 28 Feb. 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