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