pho·to·sphere | \ˈfō-tə-ˌsfir \

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, -ˈsfer- \ adjective

Examples of photosphere in a Sentence

Recent Examples on the Web

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 The photosphere has a temperature of between 4,500 and 6,000 degrees Kelvin, while the corona's temperatures are more like 1,000,000 or 2,000,000 K and can blaze as hot as 20,000,000 K in the right conditions. Jay Bennett, Popular Mechanics, "NASA Is Building a Spacecraft That Will Fly Into the Sun's Atmosphere," 30 Mar. 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

The first known use of photosphere was in 1664

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