red giant star
Quick Summary
A red giant is a star that has a low surface temperature and a diameter significantly larger than the Sun. These stars represent a later stage in a star's life cycle, occurring after a star exhausts its hydrogen fuel and leaves the main sequence.12
As a star like our Sun ages, its core contracts and heats up, causing its outer layers to expand and cool. This expansion leads to the star becoming a red giant. In stars of low to intermediate mass, helium fusion begins in the core, creating heavier elements. Eventually, these stars shed their outer layers, forming planetary nebulae and leaving behind a white dwarf, which is a dense remnant of the core.23
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planetary nebulaEvolution of planetary nebulae…the central star is a red giant before the ejection. In such a phase it experiences a rapid loss of mass, up to 0.01 Earth mass per day, in the form of a comparatively slowly expanding stellar wind. At this stage the red giant might be heavily obscured by dust…
Read More…the central star is a red giant before the ejection. In such a phase it experiences a rapid loss of mass, up to 0.01 Earth mass per day, in the form of a comparatively slowly expanding stellar wind. At this stage the red giant might be heavily obscured by dust…
Read More- planetary nebulaThe nature of the progenitor stars
…that the progenitor was a red giant star, large and cool, completely unlike the small, hot, blue, nuclear star remaining after the ejection. Likely candidates are members of the class of long-period variable stars, which have about the right size and mass and are known to be unstable. Symbiotic stars…
Read More…that the progenitor was a red giant star, large and cool, completely unlike the small, hot, blue, nuclear star remaining after the ejection. Likely candidates are members of the class of long-period variable stars, which have about the right size and mass and are known to be unstable. Symbiotic stars…
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nebulaClasses of nebulae…massive enough to become supernovae—namely, red giant stars. That is to say, a red giant has shed its outer envelope in a less-violent event than a supernova explosion and has become an intensely hot star surrounded by a shell of material that is expanding at a speed of tens of…
Read More…massive enough to become supernovae—namely, red giant stars. That is to say, a red giant has shed its outer envelope in a less-violent event than a supernova explosion and has become an intensely hot star surrounded by a shell of material that is expanding at a speed of tens of…
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nova…are aged: one is a red giant and the other a white dwarf. In certain cases, the red giant expands into the gravitational domain of its companion. The gravitational field of the white dwarf is so strong that hydrogen-rich matter from the outer atmosphere of the red giant is pulled…
Read More…are aged: one is a red giant and the other a white dwarf. In certain cases, the red giant expands into the gravitational domain of its companion. The gravitational field of the white dwarf is so strong that hydrogen-rich matter from the outer atmosphere of the red giant is pulled…
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white dwarf star…red-giant phase—the star becomes a red giant for a second time. Near the end of this second red-giant phase, the star loses its extended envelope in a catastrophic event, leaving behind a dense, hot, and luminous core surrounded by a glowing spherical shell. This is the planetary-nebula phase. During the…
Read More…red-giant phase—the star becomes a red giant for a second time. Near the end of this second red-giant phase, the star loses its extended envelope in a catastrophic event, leaving behind a dense, hot, and luminous core surrounded by a glowing spherical shell. This is the planetary-nebula phase. During the…
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