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Emission Line

Astronomy  Emission  Emission Nebula

Emission Line
An emission line will appear in a spectrum if the source emits specific wavelengths of radiation. This emission occurs when an atom, element or molecule in an excited state returns to a configuration of lower energy.


s are used in physics, chemistry, and astronomy to determine what kind of gas is doing the emission. Every element has a different electronic structure, and will thus have a different fingerprint.

Emission lines in accreting binaries
Accreting binary systems (Cataclysmic Variables and X-ray Binaries) are among the strongest sources of X-rays on the sky.

S
The spectra we encountered in Chapter 3 are examples of continuous spectra.

emission line: a more or less narrow range of wavelengths in a spectrum that is brighter than neighboring wavelengths. Emission lines are seen in quasars.

Variability of the Accreting Young Brown Dwarf 2MASSW J1207334-393254: From Hours to Years
July 13, 2007 STELZER B., SCHOLZ A. & JAYAWARDHANA R.
ApJ.
preprint ...

Emission lines and the far-UV spectrum. Since recombination lines (and a few others) are powered ultimately by parts of the spectrum we can't see directly, they may give our only information on what happens between the UV and soft X-ray ranges.

: A bright line in a spectrum caused by the emission of photons from atoms.
Emission Nebula: A cloud of gas that is excited by the ultraviolet radiation from hot stars.

emission line spectrum
A spectrum that contains bright emission lines.
emission nebula
A glowing gaseous nebula whose spectrum has bright emission lines.


A bright line in a spectrum caused by the emission of photons from atoms.
Emission Nebula ...

Emission lines. Specific wavelengths of light that are brighter than adjoining wavelengths seen in spectra.
Ephemeris. A table or list of the predicted position of an object such as a planet.

- A narrow, bright region of the spectrum. s are produced when electrons in atoms jump from one energy level to lower energy level
Energy Flux - The rate at which a wave carries energy through a given area ...

emission line
Within a spectrum, an excess amount of energy that is emitted at a specific wavelength. Emission lines in a spectrum usually appear as slender slivers of light on a dark background.

s
Bright lines produced in a spectrum by a luminous source, such as a star or a bright nebula. Compare absorption lines.
Emission Measure (EM) ...

The Emission Line Corona
Click on image for larger version.
Early observations of the visible spectrum of the corona revealed bright emission lines at wavelengths that did not correspond to any known materials.

Narrow Galaxy
Neodymium
A toxic silvery element belonging to the lanthanoid series of metals. It occurs in association with other lanthanoids.

Emission lines
Absorption lines
A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from an excess or deficiency of photons in a narrow frequency range, compared with the nearby frequencies.

Bright line in a specific location of the spectrum of radiating material, corresponding to emission of light at a certain frequency.

emission line - A discrete bright spectral line.
ephemeris - A table that gives the position of a celestial body at various times, or other astronomical data.

s are produced by hot gas. If the hot gas is moving at a pretty good rate of speed, then the Doppler effect comes into play - the s could be shifted to different wavelengths.

Emission Lines: The bright lines seen against a darker background, created when a hot gas emits photons characteristic of the elements of which the gas is composed.


In spectroscopy, a particular wavelength of emitted radiation, more intense than the background continuum.
emission measure ...

emission line - (n.)
A wavelength at which radiation is emitted, creating a bright line in the spectrum.
emission nebula - (n.) ...

s with peculiarity
eq
s with ^P-Cygni//gr 304.446667, 38.032944^ profile
ev ...

The emission line for Fe XI, occurs at 789.2 nanometres (nm), and the first images of the corona at this wavelength reveal some surprises, ...

21-cm
The important radio radiation at 21-cm wavelength from interstellar neutral atomic hydrogen.
aberration of starlight ...

e: Emission lines are present (usually hydrogen)
m: Abnormally strong "metals" (elements other than hydrogen and helium) for a star of a given spectral type; usually applied to A stars ...

Spectral s suggest an expanding shell of gas surrounding the star.
Other Designations For This Star
Hipparcos Identifier (HIP Number) ...

What produces an emission line spectrum? Do you need a thermal source in the background?
Can you see emission lines if a thermal source is in the background? What does their visibility depend on?

A minute range of wavelength (or frequency) in the electromagnetic spectrum within which radiant energy is being emitted by a radiating substance. See spectral line, emission spectrum.

emission line emission nebula emission spectrum Spectrum containing bright lines or a set of discrete wavelengths produced in a rarefied incandescent gas.

A spectrum in which there are no absorption or s.
Corona
The faint outer atmosphere of the Sun that is exposed during a total solar eclipse.
Coronae ...

continuum The continuous spectrum that any object would produce if no absorption or emission lines were present. Any body above absolute zero emits a spectrum, the shape of which is dependant on its temperature.

See also: See also: Emission, Astro, Spectrum, Star, Solar

Astronomy  Emission  Emission Nebula

 
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