Cepheid
Americannoun
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Cepheids
plural
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Any of a class of variable stars whose luminosity fluctuates with an extremely regular period. There is a strong correlation between the absolute magnitude of a Cepheid's luminosity and its period. By comparing the apparent magnitude of a Cepheid to the absolute magnitude corresponding to its period, it is possible to determine fairly accurately how distant the Cepheid is from Earth.
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Also called Cepheid variable
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Noun Inflected Forms
Example Sentences
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After the deal closes, Masimo is expected to operate as a stand-alone company within Danaher’s Diagnostics segment, alongside other businesses Radiometer, Leica Biosystems, Cepheid and Beckman Coulter Diagnostics, the people familiar with the matter said.
From The Wall Street Journal ● Feb. 17, 2026
The Washington, D.C.–based conglomerate makes medical and scientific tools, spanning research to diagnostics, including Covid tests by its Cepheid division—one of the first-approved and widely used versions.
From Barron's ● Jan. 8, 2026
He calculated M31’s distance as a prodigious 900,000 light years away, though he underestimated its true distance – about 2.5 million light years – by not realizing there were two different types of Cepheid variables.
From Salon ● Feb. 14, 2025
But some astronomers suggested that, moving outward along the "second rung," the cosmic distance ladder might get shaky if the Cepheid measurements become less accurate with distance.
From Science Daily ● Mar. 11, 2024
Cepheid stars pulsate, getting brighter and dimmer in a very predictable way; the way they pulsate is closely related to how much light they put out.
From "Zero: The Biography of a Dangerous Idea" by Charles Seife
By the end of 1924, he had found 12 Cepheids in M31.
From Salon ● Feb. 14, 2025
Webb slices though the dust and naturally isolates the Cepheids from neighboring stars because its vision is sharper than Hubble's at infrared wavelengths.
From Science Daily ● Mar. 11, 2024
A key rung relies on observations of variable stars called Cepheids.
From Science Magazine ● Oct. 31, 2023
Researchers at the University of Warsaw measured the positions of 2,431 supergiant stars known as Cepheids using the Optical Gravitational Lensing Experiment telescope at Las Campanas Observatory in Chile.
From Nature ● Aug. 6, 2019
Leavitt’s genius was to realize that by comparing the relative magnitudes of Cepheids at different points in the sky you could work out where they were in relation to each other.
From "A Short History of Nearly Everything" by Bill Bryson
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
