main sequence star
Quick Summary
A main-sequence star is a star that is in the longest and most stable phase of its life cycle. During this stage, stars fuse hydrogen into helium in their cores, releasing energy. This process creates a balance between gravity pulling inward and the outward pressure from nuclear fusion.12
Stars begin as protostars in molecular clouds, collapsing under gravity until nuclear fusion ignites in their core, marking their transition to the main sequence. The duration of this phase varies with a star's mass; more massive stars burn fuel faster and have shorter main-sequence lifespans, while less massive stars can last for billions or even trillions of years. Our Sun is a main-sequence star and is expected to remain so for about 10 billion years.134
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astronomyMeasuring observable stellar properties…of hydrostatic equilibrium are termed main-sequence stars, and they occupy a well-defined band on the Hertzsprung-Russell (H-R) diagram, in which luminosity is plotted against colour index or temperature. Spectral classification, based initially on the colour index, includes the major spectral types O, B, A, F, G, K and M, each…
Read More…of hydrostatic equilibrium are termed main-sequence stars, and they occupy a well-defined band on the Hertzsprung-Russell (H-R) diagram, in which luminosity is plotted against colour index or temperature. Spectral classification, based initially on the colour index, includes the major spectral types O, B, A, F, G, K and M, each…
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starHertzsprung-Russell diagramThese stars range from hot, O- and B-type, blue objects at least 10,000 times brighter than the Sun down through white A-type stars such as Sirius to orange K-type stars such as Epsilon Eridani and finally to M-type red dwarfs thousands of times fainter than the…
Read MoreThese stars range from hot, O- and B-type, blue objects at least 10,000 times brighter than the Sun down through white A-type stars such as Sirius to orange K-type stars such as Epsilon Eridani and finally to M-type red dwarfs thousands of times fainter than the…
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