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

There’s also that classic album cover, which Rolling Stone named as the greatest ever — a haunting image of a pulsar, lonely out in space, 978 light years away. —Rob Sheffield, Rolling Stone, 28 Apr. 2025

Radio pulsars, by comparison, produce much shorter signals — often mere seconds. —Paul Smaglik, Discover Magazine, 12 Mar. 2025

Previously, radio observatories searched the sky for new pulsars but rarely lingered long enough to pick up slower signals. —Bydaniel Clery, science.org, 4 Dec. 2024

Luckily for scientists, this rapid spin and its precise frequency make pulsars excellent timing mechanisms. —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