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.
nebular gas and dust that glows as a result of atoms being excited by high energy radiation from hot, massive, young stars.
Emission nebula create their own light. Some stars emit so much light and radiation that they actually cause nearby nebulae to glow with energy, much in the same way that the electric current in a flourescent light causes the gas inside to light up. Hydrogen in these nebulae gives off a red glow, while oxygen appears green. You can find more information at The Columbia Encyclopedia. Be sure to check out some spectacular Hubble Space Telescope photos of nebulae.
type of bright nebula consisting of glowing gas, primarily hydrogen, which can be excited or ionized by the action of ultraviolet radiation from nearby or embedded hot stars. Intense hydrogen emission can produce a pinkish color while other glowing gases can produce other hues (e.g., oxygen often gives rise to a greenish tinge).
a cloud of gas and dust, the atoms of which give off light from being excited by massive hot stars within the nebula itself
a cloud of hydrogen gas ionized by the strong radiation from hot, young stars and glowing like a neon sign
a glowing gas cloud with a hot bright star within or behind it
a nebula that emits light resulting from free electrons combining with protons to form hydrogen atoms
a nebula which is close to a star (or several stars) emitting short - wave (blue or ultraviolet ) radiation
a type of nebula that emits its own light due to the presence of ultraviolet radiation from very hot young stars inside
A cloud of gas that is excited by the ultraviolet radiation from hot stars.
A bright cloud of self-illuminating interstellar gas. Hot young stars within the cloud pump out intense ultraviolet radiation which ionizes the gas, causing it to fluoresce. M17, the Swan nebula, is a classic example.
A glowing cloud of hot interstellar gas. The gas glows as a result of a nearby young star which is ionizing the gas. Since this gas is mostly hydrogen, the emitted radiation falls predominantly in the red region of a spectrum, because of a dominant hydrogen emission.
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. In one of the most common "steps," the recombining electron emits a photon of red light. Since many atoms in the nebula do this all at once, the nebula appears red in color. This type of nebula is created when energetic ultraviolet light from a hot star shines on a cloud of hydrogen gas, stripping away electrons from the atoms (ionization). The free electrons can then begin the process of recombination. Plural of nebula: nebulae.
A gas cloud that receives energy from a hot star, allowing it to give off radiation in emission lines. These nebula are often very beatiful to look at. Many nebulae are both emission and absorbtion. Some examples are the Horsehead Nebula and the North America Nebula. See also: Absorbtion Nebula.
A gaseous nebula that derives its visible light from the fluorescence of ultraviolet light from a star in or near the nebula.
A nebula that emits light and glows
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. Emission nebulae are formed when energetic ultraviolet light from a very hot star excites a cloud of hydrogen gas; the UV radiation ionizes the hydrogen (it strips electrons from the hydrogen atoms). The free electrons combine with protons, forming hydrogen and red light. The Horsehead Nebula is in front of an emission nebula which illuminates the outline of the "horse head."
A cloud of gas excited by UV wavelengths of hot stars
A nebula which emits radiation, often in the form ofvisible light, due to the excitation of gas and dust by stars within the nebula itself (eg. Orion, Lagoon, Trifid, Eagle nebulae).
a gas cloud radiating by stimulated emission
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. Among the several different types of emission nebula are H II regions, in which star formation is taking place and young, massive stars are the source of the ionising photons; and planetary nebulae, in which a dying star has thrown off its outer layers, with the exposed hot core then ionizing them.