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What causes the dark lines in a stars spectrum?
Fraunhofer lines, in astronomical spectroscopy, any of the dark (absorption) lines in the spectrum of the Sun or other star, caused by selective absorption of the Sun’s or star’s radiation at specific wavelengths by the various elements existing as gases in its atmosphere.
What do dark lines in a spectrum mean?
When we see dark lines in a spectrum, they correspond to certain wavelengths being missing due to absorption by matter (in the form of atoms/molecules) on their way. So the dark line represents “absence of light” in a spectrum, not any particular wavelength (color) of light.
What causes lines in a line spectrum?
Spectral lines are produced by transitions of electrons within atoms or ions. As the electrons move closer to or farther from the nucleus of an atom (or of an ion), energy in the form of light (or other radiation) is emitted or absorbed.…
What does the spectra of a star tell us?
From spectral lines astronomers can determine not only the element, but the temperature and density of that element in the star. The spectral line also can tell us about any magnetic field of the star. The width of the line can tell us how fast the material is moving.
What does the spectrum of a star tell us?
Why are spectral lines useful in classifying stars quizlet?
Spectral class corresponds to temperature. from relative strengths of absorption lines in a star’s spectrum. narrow, the star’s diameter is large. If the lines are wider, the star’s diameter is smaller.
Why do stars have an absorption line spectra?
Stars have absorption line spectra. We can think of stars as a hot continuum source with a “cool” atmosphere of absorbing gas. The wavelengths that get absorbed depend on the chemical make up of the gas in the stellar atmosphere.
Why are the emission lines of a star called that?
If the cloud gives off more light than it absorbs, the spectrum at the left will have a peak instead of a valley. These peaks are called “emission lines,” because the cloud emits light. Emission lines also depend on the temperature of a star; they only appear if a star is at the right temperature.
Why are dark lines in an absorption line spectrum from the Sun?
When a photon is absorbed, it does not reach your eyes anymore, so for that specific wavelength the image gets darker. In the spectrum this wavelength is suppressed. The reemitted photon is sent off in a random direction.
Are there any breaks in the spectrum of a star?
If you were to observe the star (a source of white light) directly, you would see a continuous spectrum, with no breaks.