Ce·​phe·​id ˈse-f(ē-)id How to pronounce Cepheid (audio) ˈsē- How to pronounce Cepheid (audio)
: any of a class of variable stars whose very regular light variations are related directly to their intrinsic luminosities and whose apparent luminosities are used to estimate distances in astronomy

Examples of Cepheid in a Sentence

Recent Examples on the Web The diagnostics company Cepheid also lowered the cost of one of its test cartridges for the GeneXpert after John started another online campaign. Katherine MacPhail, STAT, 16 Mar. 2024 In the nearby cosmos, scientists measure distances using stars called Cepheid variables that periodically change in brightness. Quanta Magazine, 19 Jan. 2024 The standard candle that Hubble used in plotting his diagram was a Cepheid variable, a star that brightens and dims at regular intervals. Richard Panek, Scientific American, 14 Nov. 2023 Energized by the finding, Hubble carried out the calculations and realized the Cepheid had led him to an even greater discovery. Corinne Purtill, Los Angeles Times, 3 Oct. 2023 This collection of 36 images from NASA’s Hubble Space Telescope features galaxies that are all hosts to both Cepheid variables and supernovae. Paul M. Sutter, Popular Mechanics, 3 Jan. 2023 This collection of 37 images from the Hubble Space Telescope, taken between 2003 and 2021, includes galaxies that are all hosts to both Cepheid variables and supernovae. Ashley Strickland, CNN, 23 May 2022 With roughly $135 million in funding from the federal government, more Cepheid machines are being added at health clinics across the city for the purpose of Covid-19 testing. Melanie Grayce West, WSJ, 14 Oct. 2020 So the Cepheid GeneXpert probably would be more fit to purpose. CBS News, 4 Oct. 2020

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'Cepheid.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


International Scientific Vocabulary, from Cepheus

First Known Use

circa 1903, in the meaning defined above

Time Traveler
The first known use of Cepheid was circa 1903

Dictionary Entries Near Cepheid

Cite this Entry

“Cepheid.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/Cepheid. Accessed 20 May. 2024.

Kids Definition


Ce·​phe·​id ˈsē-fē-əd How to pronounce Cepheid (audio)
: one of a class of pulsating stars whose changes in brightness are very regular
Last Updated: - Updated example sentences
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