photosphere

noun

pho·​to·​sphere ˈfō-tə-ˌsfir How to pronounce photosphere (audio)
1
: a sphere of light or radiance
2
: the luminous surface layer of the sun or a star
photospheric adjective

Examples of photosphere in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The sun's photosphere, its surface, is about 10,000 degrees Fahrenheit (5,500 degrees Celsius), but the corona is two million degrees Fahrenheit (over 1,1 million degrees C) — about 200 times hotter. Jamie Carter, Space.com, 16 June 2025 This allows the researchers to separately image the photosphere, chromosphere, interface region, and corona. Because the spectrograph is fast, IRIS can combine big images with very fine spectra of every 240-km-wide slice of the scene. IEEE Spectrum, 12 Dec. 2013 In November, the ESA released images the Solar Orbiter obtained in March 2023 that the agency said are the highest-resolution views of the sun's surface, known as the photosphere, to date. Eric Lagatta, USA Today, 13 June 2025 The images show ultra-fine bright and dark stripes (called striations) in the thin, gaseous layer of the sun's atmosphere known as the photosphere, according to a statement from the National Solar Observatory (NSO), which operates the solar telescope. Samantha Mathewson, Space.com, 6 June 2025 See All Example Sentences for photosphere

Word History

Etymology

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

First Known Use

1664, in the meaning defined at sense 1

Time Traveler
The first known use of photosphere was in 1664

Browse Nearby Words

Cite this Entry

“Photosphere.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/photosphere. Accessed 4 Jul. 2025.

Kids Definition

photosphere

noun
pho·​to·​sphere ˈfōt-ə-ˌsfi(ə)r How to pronounce photosphere (audio)
: the shining surface of the sun or a star
photospheric adjective

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