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Astro*Dictionary by Michael Erlewine





3 articles for "Emission"

Emission Nebula [Astro*Index]

A collection of interstellar gaseous matter which absorbs energy from nearby stars and emits that energy as visible light.

See also: ♦ Nebulae ♦ Light Spectrum
Emission Spectrum [Astro*Index]

An incandescent gas under low pressure produces a bright-line (or emission) spectrum, with positions of the lines characteristic of the chemical nature of the gas. The presence of a element is easily determined, as no two elements have spectra with even a single line in common. And, the spectra of some metals have thousands of lines. Spectral Analysis is the principal method used to determine the chemical composition of stars.

See also: ♦ Light Spectrum
Emission Star [Astro*Index]

A type of star whose spectrum shows bright emission lines. These bright lines are due to the absorption and re-emission of the star's energy by an expanding shell of gases which surround the star.

See also: ♦ Emission Spectrum


Astro*Index Copyright © 1997 Michael Erlewine