pho·​to·​sphere | \ ˈfō-tə-ˌsfir How to pronounce photosphere (audio) \

Definition of photosphere

1 : a sphere of light or radiance
2 : the luminous surface layer of the sun or a star

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Other Words from photosphere

photospheric \ ˌfō-​tə-​ˈsfir-​ik How to pronounce photosphere (audio) , -​ˈsfer-​ \ adjective

Examples of photosphere in a Sentence

Recent Examples on the Web As far as is known, no comets have ever actually been seen to hit the solar surface, or the photosphere, the European Space Agency said. Katie Hunt, CNN, "Newly discovered comet photographed during solar eclipse," 21 Dec. 2020 By the time this acceleration reached its peak, the photosphere was moving at about seven kilometers a second. John Timmer, Ars Technica, "Astronomers kill all the fun, blame dust for Betelgeuse’s dimming," 14 Aug. 2020 This set of magnetometers will measure magnetic variation throughout the spacecraft's orbit, which rangers from out beyond Venus to a close distance of 9 solar radii, or only 3.85 million miles from the photosphere. Jay Bennett, Popular Mechanics, "The New Science of the Sun Will Be Astounding—And Possibly Terrifying," 9 Aug. 2018 This instrument will measure magnetic and electric fields in the sun's atmosphere to help scientists better understand why the corona is so much hotter than the photosphere. Elizabeth Howell,, "Here Comes the Sun! Parker Solar Probe Instruments See 'First Light'," 25 Sep. 2018 Even when 99 percent of the sun's surface (the photosphere) is obscured during the partial phases of a solar eclipse, the remaining crescent Sun is still intense enough to cause a retinal burn. Leada Gore,, "Solar eclipse 2017: Why is it dangerous to watch a total solar eclipse?," 4 Aug. 2017 If skies are clear, observers will be able to see the sun’s halo-like corona, which is usually obscured by the brightness of the photosphere. Deborah Netburn,, "Parades, parties and port-a-potties: Eclipse mania is taking hold from coast to coast," 20 July 2017 But just a few hundred miles above the photosphere, in the star's corona, the temperature suddenly jumps to several million degrees. William Harwood, CBS News, "NASA solar probe to "touch" sun's atmosphere," 31 May 2017 The visible surface of the sun, the photosphere, has a temperature of about 6,000 degrees Fahrenheit. William Harwood, CBS News, "NASA solar probe to "touch" sun's atmosphere," 31 May 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'photosphere.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of photosphere

1664, in the meaning defined at sense 1

History and Etymology for photosphere

photo- + -sphere; in sense 2 probably as translation of German Lichtatmosphäre

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Time Traveler for photosphere

Time Traveler

The first known use of photosphere was in 1664

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Statistics for photosphere

Last Updated

9 Jan 2021

Cite this Entry

“Photosphere.” Dictionary, Merriam-Webster, Accessed 26 Feb. 2021.

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