9/21/2023 0 Comments Define main sequence star![]() Representative stages in postMain Sequence evolution. When the star can no longer provide enough hydrostatic support, it will eventually collapse due to its own gravity. A major grouping of stars that forms a relatively narrow band from the upper left to the lower right when plotted according to luminosity and surface. Astronomers refer to the aging of a star as stellar evolution. But, after the main sequence, the star has already used up its nuclear fuel in its core. As the stars evolve, they adjust to the increase in the helium-to-hydrogen ratio in. Without differences in initial chemical composition or in rotational velocity, all the stars would start exactly from this unique line. the Hertzsprung-Russell diagram called the zero-age main sequence. During this time, the contraction of the star which generated heat provides hydrostatic support. In star: Subsequent development on the main sequence. A star first forms out of a cold cloud of molecular hydrogen and helium. This long phase of the life of a star is called the main sequence.īefore the main sequence phase, a star’s interior is not yet dense enough to begin nuclear reaction. Let’s example the main sequence phase of a star’s life and see what role it plays in a star’s evolution. Main sequence star: a star 0. The surface is thus very different from the relatively quiescent photosphere of a pre-main sequence or main-sequence star. The nuclear reactions near the center of the star provide interior heat and the radiation for the most part of a star’s life span. Regardless of the details, the outer surface of a protostar consists at least partially of shocked gas that has fallen from the inner edge of the disk. However, it is counterbalanced by the radiation emitted in the interior of the star, called the hydrostatic support. This gravity tends to cause a star to collapse. The mass of the star is the most important factor to determine the lifespan, the size and the luminosity of a main sequence star.Ī star is composed of gas, held together into a sphere by its own gravity. ![]() The bigger the mass of the star, the more hydrogen it can fuse into helium. The rate of this fusion varies relative to the mass of the star. A star fuels itself by continually fusing hydrogen into helium within its core. Main sequence stars are classified by their energy source. Most of the stars in the galaxy, including the Sun, are considered as main sequence stars.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |