The effective temperature of a body such as a star or planet is the temperature of a black body that would emit the same total amount of electromagnetic radiation. Effective temperature is often used as an estimate of a body's temperature when the body's emissivity curve (as a function of wavelength) is not known.
When the star's or planet's net emissivity in the relevant wavelength band is less than unity (less that that of a black body), 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, including greenhouse effect.
Famous quotes containing the words effective and/or temperature:
“I know no method to secure the repeal of bad or obnoxious laws so effective as their stringent execution.”
—Ulysses S. Grant (1822–1885)
“The siren south is well enough, but New York, at the beginning of March, is a hoyden we would not care to miss—a drafty wench, her temperature up and down, full of bold promises and dust in the eye.”
—E.B. (Elwyn Brooks)