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main sequence

noun, Astronomy.
a narrow band in the Hertzsprung-Russell diagram in which 90 percent of all observed stars are plotted.
Origin of main sequence
1925-30 Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2016.
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British Dictionary definitions for main sequence

main sequence

  1. a diagonal band on the Hertzsprung Russell diagram containing about 90% of all known stars; stars evolve onto and then off the band during their lifetime
  2. (as modifier): a main-sequence star
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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main sequence in Science
main sequence
The continuous, generally diagonal line or band in the Hertzsprung-Russell diagram ranging from the upper left to the lower right and representing stars of average size whose luminosities correspond predictably to their surface temperatures. Stars in this grouping maintain a stable nuclear reaction and experience only small fluctuations in luminosity and temperature. Main-sequence stars are believed to be in the stable, middle phase of their development; they are expected to move off the main sequence once the hydrogen in their core is exhausted. At that point, depending on its size, a main-sequence star will become a giant star, a supergiant star, or a white dwarf. The more massive the star, the faster it burns its nuclear fuel and the shorter it remains in the main sequence. See more at Hertzsprung-Russell diagram, star.

The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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