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Index H-alpha

H-alpha (Hα) is a specific deep-red visible spectral line in the Balmer series with a wavelength of 656.28 nm in air; it occurs when a hydrogen electron falls from its third to second lowest energy level. [1]

39 relations: Acetonitrile, Ammonia, Astronomy, Astrophotography, Atom, Atomic nucleus, Ångström, Balmer series, Bandwidth (signal processing), Bohr model, Carbon dioxide, Carbon monoxide, Chromosphere, Dichroic filter, Doppler effect, Electromagnetic spectrum, Electron, Emission nebula, Fabry–Pérot interferometer, Formaldehyde, Hydrogen, Hydrogen spectral series, Light pollution, Lyman series, Lyot filter, Nanometre, Nebula, Optical filter, Photon, Principal quantum number, Quantum, Rydberg formula, Solar prominence, Spectral line, Spectrohelioscope, Springer Science+Business Media, Sun, Wave interference, Wavelength.


Acetonitrile is the chemical compound with the formula.

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Ammonia is a compound of nitrogen and hydrogen with the formula NH3.

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Astronomy (from ἀστρονομία) is a natural science that studies celestial objects and phenomena.

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Astrophotography is a specialized type of photography for recording photos of astronomical objects, celestial events, and areas of the night sky.

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An atom is the smallest constituent unit of ordinary matter that has the properties of a chemical element.

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Atomic nucleus

The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford based on the 1909 Geiger–Marsden gold foil experiment.

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The ångström or angstrom is a unit of length equal to (one ten-billionth of a metre) or 0.1 nanometre.

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Balmer series

The Balmer series or Balmer lines in atomic physics, is the designation of one of a set of six named series describing the spectral line emissions of the hydrogen atom.

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Bandwidth (signal processing)

Bandwidth is the difference between the upper and lower frequencies in a continuous band of frequencies.

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Bohr model

In atomic physics, the Rutherford–Bohr model or Bohr model or Bohr diagram, introduced by Niels Bohr and Ernest Rutherford in 1913, depicts the atom as a small, positively charged nucleus surrounded by electrons that travel in circular orbits around the nucleus—similar to the structure of the Solar System, but with attraction provided by electrostatic forces rather than gravity.

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Carbon dioxide

Carbon dioxide (chemical formula) is a colorless gas with a density about 60% higher than that of dry air.

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Carbon monoxide

Carbon monoxide (CO) is a colorless, odorless, and tasteless gas that is slightly less dense than air.

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The chromosphere (literally, "sphere of color") is the second of the three main layers in the Sun's atmosphere and is roughly 3,000 to 5,000 kilometers deep.

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Dichroic filter

A dichroic filter, thin-film filter, or interference filter is a very accurate color filter used to selectively pass light of a small range of colors while reflecting other colors.

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Doppler effect

The Doppler effect (or the Doppler shift) is the change in frequency or wavelength of a wave in relation to observer who is moving relative to the wave source.

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Electromagnetic spectrum

The electromagnetic spectrum is the range of frequencies (the spectrum) of electromagnetic radiation and their respective wavelengths and photon energies.

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The electron is a subatomic particle, symbol or, whose electric charge is negative one elementary charge.

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Emission nebula

An emission nebula is a nebula formed of ionized gases that emit light of various wavelengths.

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Fabry–Pérot interferometer

In optics, a Fabry–Pérot interferometer (FPI) or etalon is typically made of a transparent plate with two reflecting surfaces, or two parallel highly reflecting mirrors.

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No description.

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Hydrogen is a chemical element with symbol H and atomic number 1.

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Hydrogen spectral series

The emission spectrum of atomic hydrogen is divided into a number of spectral series, with wavelengths given by the Rydberg formula.

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Light pollution

Light pollution, also known as photopollution, is the presence of anthropogenic light in the night environment.

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Lyman series

In physics and chemistry, the Lyman series is a hydrogen spectral series of transitions and resulting ultraviolet emission lines of the hydrogen atom as an electron goes from n ≥ 2 to n.

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Lyot filter

A Lyot filter, named for its inventor Bernard Lyot, is a type of optical filter that uses birefringence to produce a narrow passband of transmitted wavelengths.

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The nanometre (International spelling as used by the International Bureau of Weights and Measures; SI symbol: nm) or nanometer (American spelling) is a unit of length in the metric system, equal to one billionth (short scale) of a metre (m).

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A nebula (Latin for "cloud" or "fog"; pl. nebulae, nebulæ, or nebulas) is an interstellar cloud of dust, hydrogen, helium and other ionized gases.

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Optical filter

An optical filter is a device that selectively transmits light of different wavelengths, usually implemented as a glass plane or plastic device in the optical path, which are either dyed in the bulk or have interference coatings.

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The photon is a type of elementary particle, the quantum of the electromagnetic field including electromagnetic radiation such as light, and the force carrier for the electromagnetic force (even when static via virtual particles).

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Principal quantum number

In quantum mechanics, the principal quantum number (symbolized n) is one of four quantum numbers which are assigned to all electrons in an atom to describe that electron's state.

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In physics, a quantum (plural: quanta) is the minimum amount of any physical entity (physical property) involved in an interaction.

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Rydberg formula

The Rydberg formula is used in atomic physics to describe the wavelengths of spectral lines of many chemical elements.

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Solar prominence

A prominence is a large, bright, gaseous feature extending outward from the Sun's surface, often in a loop shape.

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Spectral line

A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from emission or absorption of light in a narrow frequency range, compared with the nearby frequencies.

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A spectrohelioscope is a type of solar telescope designed by George Ellery Hale in 1924 to allow the Sun to be viewed in a selected wavelength of light.

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Springer Science+Business Media

Springer Science+Business Media or Springer, part of Springer Nature since 2015, is a global publishing company that publishes books, e-books and peer-reviewed journals in science, humanities, technical and medical (STM) publishing.

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The Sun is the star at the center of the Solar System.

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Wave interference

In physics, interference is a phenomenon in which two waves superpose to form a resultant wave of greater, lower, or the same amplitude.

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In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats.

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[1] https://en.wikipedia.org/wiki/H-alpha

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