Most%20of%20what%20is%20known%20about%20stars%20comes%20from%20spectral%20studies.

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Most of what is known about stars comes from
spectral studies.
There are 3 kinds of visible spectra Continuous,
bright-line and dark-line.
Continuous unbroken band of colors from a
source sending out all visible wavelengths.
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Continuous spectra can come from a (hot) glowing
solid, a glowing liquid or a glowing gas (star).
Bright-line spectrum also called an emission
spectrum, is a series of unevenly spaced lines of
different colors and brightness.
Hydrogen emission spectrum
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Every element has its own unique bright-line
spectrum, like a fingerprint.
Helium emission spectrum
Dark-line spectrum a continuous spectrum with
dark lines where light has been absorbed.
(absorption spectrum)
Helium absorption spectrum
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The dark lines are in the exact same place as the
bright lines would be for the same element in a
bright-line spectrum.
The dark lines are formed when light passes
through a cooler gas. The dark lines tell us what
gases are in the atmospheres of stars and planets.
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Dark-line spectrum
Bright-line spectrum
Hydrogen emission spectrum
Stars (dark-line) spectra.
Blueshift
Redshift
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The student will understand the similarities and
differences between the three types of spectra.
In addition, students will understand how spectra
are used to learn about planets and stars.
Materials - Low pressure gas discharge tubes,
high voltage electrical exciter and spectroscopes.
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1. What is a continuous spectrum?
2. What is a bright line spectrum?
3. What is a dark line spectrum?
4. What does the bumper sticker mean?

If the background on this bumper-sticker appears
blue, youre going way too fast!
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