Effective temperature

<p>The effective temperature of a body such as a star or planet is the <a href="/facts/Temperature/QyGe4gmj">temperature</a> of a <a href="/facts/Black_body/f0fHghDy">black body</a> that would emit the same total amount of <a href="/facts/Electromagnetic_radiation/Ynx7ujCW">electromagnetic radiation</a>.  Effective temperature is often used as an estimate of a body's surface temperature when the body's <a href="/facts/Emissivity/LUxfMRRI">emissivity</a> curve (as a function of <a href="/facts/Wavelength/kcJU0ymz">wavelength</a>) is not known.
</p><p>When the star's or planet's net <a href="/facts/Emissivity/LUxfMRRI">emissivity</a> in the relevant wavelength band is less than unity (less than that of a <a href="/facts/Black_body/f0fHghDy">black body</a>), the actual temperature of the body will be higher than the effective temperature.  The net emissivity may be low due to surface or atmospheric properties, such as the <a href="/facts/Greenhouse_effect/LGdNYYj3">greenhouse effect</a>.
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Effective temperature open-in-new

Effective temperature