Main Sequence Definition & Meaning

American

British

Scientific

Etymology

Examples

main sequence American

noun

Astronomy.

1. a narrow band in the Hertzsprung-Russell diagram in which 90 percent of all observed stars are plotted.

main sequence British

noun

1. astronomy

   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 main sequence Scientific / mān /

1. 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.

2. See more at Hertzsprung-Russell diagram star

Etymology

Origin of main sequence

First recorded in 1925–30

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Located about 11,000 light years from Earth near the constellation Pupis, Gaia20ehk is a stable "main sequence" star similar to our sun.

From Science Daily

“There is a huge amount of all those critical minerals that are trapped in those resources and could be very important economic sources of supply,” said Jun Qu, an investment manager at Main Sequence, one of Samsara Eco’s early backers.

From The Wall Street Journal

Main Sequence, the deep-tech venture-capital firm founded by Australia’s national science agency in 2017, declined to say whether it will return for the latest round.

From The Wall Street Journal

Other investors included Australia’s Main Sequence and European strategic angel investors.

From The Wall Street Journal

Main Sequence led that raise and contributed about $1.5 million, partner Mike Zimmerman said.

From The Wall Street Journal

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.