a narrow band in the Hertzsprung-Russell diagram in which 90 percent of all observed stars are plotted.
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.
- Main-sequence star
noun any star lying on a diagonal band that extends from hot stars of high luminosity to cool stars of low luminosity; any stars in the Hertzsprung-Russell diagram from the upper left to the lower right of the diagram; also written main sequence star Examples Most stars in the Sun’s neighborhood are main sequence stars.
noun, Machinery. 1. the principal shaft of a motor, transmission, etc. (distinguished from ).
[meyn-sheet] /ˈmeɪnˌʃit/ noun, Nautical. 1. a of a mainsail. /ˈmeɪnˌʃiːt/ noun 1. (nautical) the line used to control the angle of the mainsail to the wind
[meyn-spring] /ˈmeɪnˌsprɪŋ/ noun 1. the principal in a mechanism, as in a watch. 2. the chief motive power; the impelling cause. /ˈmeɪnˌsprɪŋ/ noun 1. the principal power spring of a mechanism, esp in a watch or clock 2. the chief cause or motive of something n. 1590s, of watches, clocks, etc., from main (adj.) + […]