pho·​tom·​e·​try fō-ˈtä-mə-trē How to pronounce photometry (audio)
: a branch of science that deals with measurement of the intensity of light
also : the practice of using a photometer

Examples of photometry in a Sentence

Recent Examples on the Web The mission searched for Earth-sized planets beyond the solar system using transit photometry, a then-emerging technology which detects exoplanets by observing when the brightness of a star dips as a planet crosses in front of it. Martha Ross, The Mercury News, 25 Jan. 2024 Stellar photometry can be extended to look for exomoons, an approach pioneered by Kipping. Ivan Paul, Ars Technica, 26 Dec. 2023 The 37 boulders range in size from three feet to 22 feet across, based on Hubble photometry. Julia Musto, Fox News, 22 July 2023 The team say that the photometry suggests Earendel has a surface temperature of between 13000 and 16000 Kelvin. The Physics Arxiv Blog, Discover Magazine, 26 Aug. 2022 When the Wheel Failed Kepler was designed to stare at bright stars to look for blips in their brightness that could indicate planets passing in front of them, a technique called photometry. Guest Blogger, Discover Magazine, 20 Aug. 2013 For now the galaxies have only been studied by photometry, with spectroscopic analysis planned for July. Jonathan O'Callaghan, Scientific American, 13 Apr. 2023 Adrien Stanley, a neuroscientist in Sulzer’s lab, is using a technique called fibre photometry to trace the process in mice. Burkhard Bilger, The New Yorker, 27 Mar. 2023 One is by using optical photometry to measure the galaxies’ color. Bruce Dorminey, Forbes, 14 Feb. 2023 See More

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

Word History


New Latin photometria, from phot- + -metria -metry

First Known Use

1807, in the meaning defined above

Time Traveler
The first known use of photometry was in 1807

Dictionary Entries Near photometry

Cite this Entry

“Photometry.” Dictionary, Merriam-Webster, Accessed 25 Feb. 2024.

Medical Definition


pho·​tom·​e·​try fō-ˈtäm-ə-trē How to pronounce photometry (audio)
plural photometries
: a branch of science that deals with measurement of the intensity of light
also : the practice of using a photometer

More from Merriam-Webster on photometry

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