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.
Emission nebula
An emission nebula is a cloud of ionized gas (i.e. a plasma) emitting light of various colors. The most common source for ionization are high-energy photons emitted from a nearby hot star.
Emission nebula
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History
An emission nebula is a type of nebula that emits its own light, due to the presence of ultraviolet radiation from very hot young stars inside. Cloaking devices are useless inside emission nebulae.
Emission lines 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 emission line 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.
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.
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, ...
Radio emission. Jupiter was the first planet found (in 1955) to be a source of radiation at radio wavelengths.
Hale-Bopp Fails Emission Tests but Reveals Comet Origin
Thrill seekers may want to hitch a ride on the giant comet Hale-Bopp, but they would fail vehicle emission tests miserably.
Emission spectrum: A third possibility occurs if an observer is not looking directly at a hot black body source but instead at a diffuse cloud of gas that is not a black body.
Emission Nebula NGC1491 in Perseus
(RA 4h 03.4m , Dec. +51°19', 25 x 25 arcmin.) ...
emission line Bright line in a specific location of the spectrum of radiating material, corresponding to emission of light at a certain frequency. A heated gas in a glass container produces emission lines in its spectrum.
emission
the discharge of electromagnetic radiation from an object
emission nebula ...
Emission nebula A cloud of glowing gas excited by ultraviolet radiation from hot stars.
Ephemeris (plural ephemerides) A tabulated list of positions for an object calculated from its orbital elements.
Emission Line: 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 - More or less narrow range of wavelengths in a spectrum that is brighter than neighboring wavelengths, corresponding to emission of light at a certain frequency.
Emissions of chemicals leading to acidification
The most important gas which leads to acidification is sulfur dioxide. Emissions of nitrogen oxide
Nitrogen oxide ...
Emission or Reflection Nebula: What is the shape of the nebula? Is its brightness even or are there brighter/darker areas? Are the edges of the nebula well defined? Are there any stars within the nebula?
Emission nebula
a type of nebula that shines by emitting light when electrons recombine with protons to form hydrogen atoms. The electron frequently approaches the proton in steps emitting energy as light as it gets pulled in.
emission nebula
A glowing cloud of hot interstellar gas which is energized by imbedded hot stars.
emission line: A bright line in a spectrum caused by the emission of photons from atoms.
emission nebula: A cloud of glowing gas excited by ultraviolet radiation from hot stars.
Emission Line - A narrow, bright region of the spectrum. Emission lines 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 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.
Emission
The process of transition of an electron from an outer orbit to an inner orbit around the nucleus results in a characteristic amount of energy being radiated (as line emission) that corresponds to the lost energy of the electron.
EMISSION NEBULA
An emission nebula is a nebula that glows; it emits light energy. The reddish light is produced when electrons and protons combine, forming hydrogen atoms.
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.
UV emission from northern aurora observed by the Polar satellite (Ref)
X-ray emission from northern aurora observed by the Polar Satellite (Ref) ...
The Emission of Light
We now know something about the general nature and property of light. But how does light get produced?
Photoemission
The emission of photoelectrons by the photoelectric effect or by photoionization. [DC99]
Photographic Magnitude ...
Radio Emission. Emissions of the Sun in radio wavelengths from centimeters to dekameters, under both quiet and disturbed conditions.
Atomic Emission Spectroscopy - This method uses flame excitation; atoms are excited from the heat of the flame to emit light. This method commonly uses a total consumption burner with a round burning outlet.
Emission nebulae are the most colorful of the five main types of nebulae. They are lit internally from young stars still in their stellar nursery. The different colors are caused by the different gases and the composition of the dust in the nebula.
Emission nebula are also known as HII regions. The explanation of this nomenclature is this: The H means Hydrogen and the Roman numeral II means that the hydrogen is ionized (its electron has been stripped off by high energy photons).
Emission nebulae are composed of gases (mostly hydrogen) that have been excited by stars' emitted radiation. When gas atoms get excited, they glow like a neon sign.
Emission nebulae are clouds of high temperature gas. The atoms in the cloud are energized by ultraviolet light from a nearby star and emit radiation as they fall back into lower energy states (in much the same way as a neon light).
Emission from cold dust
Central regions of galaxies
Very cold molecular clouds
Additional Information & Images ...
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.
Emission lines 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 emission lines could be shifted to different wavelengths.
Emission spectroscopy uses the range of electromagnetic spectra in which a substance radiates.
emission nebula - (n.)
A cloud of interstellar gas that glows by the light of emission lines. The source of excitation that causes the gas to emit may be radiation from a nearby star, or heating by any of a variety of mechanisms.
energy - (n.) ...
Emission lines with ^P-Cygni//gr 304.446667, 38.032944^ profile
ev
Spectral emission that exhibits variability
f ...
An emission line in the radio region of the spectrum that is due to the "spin-flip" transition in neutral hydrogen atoms. The proton and electron making up a hydrogen atom both spin.
X-ray emission is expected in sources which contain an extremely hot gas at temperatures from a million to hundred million kelvins, in general in objects in which the atoms and/or electrons have a very high energy.
X-ray emission from stellar coronal material has been observed around Stars B and C with the Chandra X-Ray Observatory (press release; Brickhouse et al, 2001; and Nikolic et al, 1997; among others).
Radio emissions from Jupiter are detected, mystify observers.
1957
Sputnik 1 launched by the Soviet Union, the first artificial satellite.
"Be" (emission) star
Opening image: Ursa Minor's Little Dipper, with Polaris at far left.
Spectral emission lines suggest an expanding shell of gas surrounding the star.
Other Designations For This Star
Hipparcos Identifier (HIP Number) ...
Increased emissions of the greenhouse gas methane are transformed into water in the stratosphere, accounting for about a third of the observed increase in moisture there.
Stimulated emission, which is the underlying process for laser action, was first proposed by Albert Einstein in 1917.
thermal emission The process by which a body emits electromagnetic radiation as a consequence of its temperature only. thermal emissive power The rate of thermal emission of radiant energy per unit area of emitting surface.
Gamma Emission (Plasma Physics and Fusion Energy Glossary) Nuclear decay process whereby the nucleus goes from an excited state to a more stable state by emitting a gamma ray.
emission line spectrum bright lines in a spectrum that are produced by hot, thin (low-pressure) gases. Made by electrons jumping down closer to the nucleus.
A small clump of emission nebulosity formed where jets of matter streaming from newly formed stars smash into the nearby interstellar gas.
A transient enhancement of the solar RADIO EMISSION, usually associated with an ACTIVE REGION or FLARE. CARRINGTON LONGITUDE. A system of fixed longitudes rotating with the sun. CENTIMETER BURST.
farrum pancake-like structure filament a strand of cool gas suspended over the photosphere by magnetic fields, which appears dark as seen against the disk of the Sun; a filament on the limb of the Sun seen in emission against the dark sky ...
Spectral Line A line in a spectrum due to the emission or absorption of electromagnetic radiation at a discrete wavelength. Spectral lines result from discrete changes in the energy of an atom or molecule.
When looking at the spectrum of this star, a curious profile of the absorbtion lines can be seen: Instead of of a more or less symmetric line profile a broad trough with an emission peak at the red side of the trough.
spectra has been recognized, in which, as well as the usual absorption bands, bright emission lines of hydrogen appear; stars having this particular spectrum are always variable.
Operational until 1999, it was instrumental in the discovery of X-ray emissions from comets and conducted an all-sky survey in the X-ray region of the spectrum. Five other satellites launched in the 1990s are still operational.
The emission of stray light or glare from lighting fixtures in manners that counter the purpose of the light (which is to light what is below); also known as the waste of money and energy in the form of electric light, ...
 See also: Light, Energy, Earth, Time, Sun
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