Key Terms

binary stars
two stars that revolve about each other
brown dwarf
an object intermediate in size between a planet and a star; the approximate mass range is from about 1/100 of the mass of the Sun up to the lower mass limit for self-sustaining nuclear reactions, which is about 1/12 the mass of the Sun
eclipsing binary
a binary star in which the plane of revolution of the two stars is nearly edge-on to our line of sight, so that the light of one star is periodically diminished by the other passing in front of it
H–R diagram
(Hertzsprung–Russell diagram) a plot of luminosity against surface temperature (or spectral type) for a group of stars
main sequence
a sequence of stars on the Hertzsprung–Russell diagram, containing the majority of stars, that runs diagonally from the upper left to the lower right
mass-luminosity relation
the observed relation between the masses and luminosities of many (90% of all) stars
selection effect
the selection of sample data in a nonrandom way, causing the sample data to be unrepresentative of the entire data set
spectroscopic binary
a binary star in which the components are not resolved but whose binary nature is indicated by periodic variations in radial velocity, indicating orbital motion
visual binary
a binary star in which the two components are telescopically resolved
white dwarf
a low-mass star that has exhausted most or all of its nuclear fuel and has collapsed to a very small size; such a star is near its final state of life
This book was adapted from the following: Fraknoi, A., Morrison, D., & Wolff, S. C. (2016). Key Terms In Astronomy. OpenStax. under a Creative Commons Attribution License 4.0
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PPSC AST 1120: Stellar Astronomy by OpenStax is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

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