spectral type
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noun Astronomy.
a category for classifying a star, as A star or G star, according to features of its spectrum, as its shape as a function of temperature and wavelength and its absorption spectrum, that indicate the surface temperature of the star and the presence of particular atoms or molecules in its outer layers: principal types are spectral types O, B, A, F, G, K, and M.
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Also called spectral class .
Origin of spectral type
First recorded in 1920–25
Words nearby spectral type
Spectracef, spectral, spectral line, spectral luminous efficiency, spectral series, spectral type, spectra yellow, spectre, spectrin, spectro-, spectrobolometer
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Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021
Example sentences from the Web for spectral type
British Dictionary definitions for spectral type
spectral type
spectral class
noun
any of various groups into which stars are classified according to characteristic spectral lines and bands. The most important classification (Harvard classification) has a series of classes O, B, A, F, G, K, M, the series also being a scale of diminishing surface temperature
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
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Scientific definitions for spectral type
spectral type
A classification system for stars based on the strength of their spectral lines, using the letters O, B, A, F, G, K, M, L, and T to denote a range from blue (as in blue giant stars) to dim red (as in brown dwarfs). The spectrum of a star correlates with its surface temperature, ranging from over 60,000°K (O type) to less than 3,500°K (L and T types). See also Hertzsprung-Russell diagram.
The American Heritage® Science Dictionary
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