photosphere

noun

pho·​to·​sphere ˈfō-tə-ˌsfir 

1

: a sphere of light or radiance

2

: the luminous surface layer of the sun or a star

photospheric

ˌfō-tə-ˈsfir-ik 

-ˈsfer-

adjective

Examples of photosphere in a Sentence

Recent Examples on the Web

However, the corona's temperature is around 1.8 million degrees Fahrenheit (1 million degrees Celsius), 150 times hotter than the photosphere. —Jamie Carter, Forbes.com, 27 Apr. 2025

The sun's corona is always in the sky, but it's overwhelmed by the sun's photosphere, which is a million times brighter. —Jamie Carter, Forbes.com, 27 Apr. 2025

Studying the sun’s photosphere and chromosphere will allow researchers to examine how plasma flows and shifting magnetic fields interact to trigger surface eruptions. —Andrew Paul, Popular Science, 24 Apr. 2025

Around 1,000 miles closer to the source of the sun's heat, the photosphere reaches a relatively balmy 7,400 degrees Fahrenheit (4,100 degrees Celsius). —Robert Lea, Space.com, 24 Dec. 2024

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

Rhymes for photosphere

• atmosphere
• biosphere
• centromere
• chemosphere
• chromosphere
• hemisphere
• hydrosphere
• lithosphere
• mesosphere
• microsphere
• miserere
• mountaineer

Kids Definition

photosphere

noun

pho·​to·​sphere ˈfōt-ə-ˌsfi(ə)r 

: the shining surface of the sun or a star

photospheric

ˌfōt-ə-ˈsfir-ik 

-ˈsfer-

adjective