Search results
Sep 16, 2020 · A low-mass star has a mass eight times the Sun’s or less and can burn steadily for billions of years. As it reaches the end of its life, its core runs out of hydrogen to convert into helium. Because the energy produced by fusion is the only force fighting gravity’s tendency to pull matter together, the core starts to collapse.
This collapse is the final event in the life of the core. Because the star’s mass is relatively low, it cannot push its core temperature high enough to begin another round of fusion (in the same way larger-mass stars can). The core continues to shrink until it reaches a density equal to nearly a million times the density of water!
- A Star in Crisis
- Degenerate Stars
- White Dwarfs
- The Ultimate Fate of White Dwarfs
- Evidence That Stars Can Shed A Lot of Mass as They Evolve
- Glossary
In the last chapter, we left the life story of a star with a mass like the Sun’s just after it had climbed up to the red-giant region of the H–R diagram for a second time and had shed some of its outer layers to form a planetary nebula. Recall that during this time, the coreof the star was undergoing an “energy crisis.” Earlier in its life, during ...
Because white dwarfs are far denser than any substance on Earth, the matter inside them behaves in a very unusual way—unlike anything we know from everyday experience. At this high density, gravity is incredibly strong and tries to shrink the star still further, but all the electrons resist being pushed closer together and set up a powerful pressur...
White dwarfs, then, are stable, compact objects with electron-degenerate cores that cannot contract any further. Calculations showing that white dwarfsare the likely end state of low-mass stars were first carried out by the Indian-American astrophysicist Subrahmanyan Chandrasekhar. He was able to show how much a star will shrink before the degenera...
If the birth of a main-sequence star is defined by the onset of fusion reactions, then we must consider the end of all fusion reactions to be the time of a star’s death. As the core is stabilized by degeneracy pressure, a last shudder of fusion passes through the outside of the star, consuming the little hydrogen still remaining. Now the star is a ...
Whether or not a star will become a white dwarf depends on how much mass is lost in the red-giant and earlier phases of evolution. All stars that have masses below the Chandrasekhar limit when they run out of fuel will become white dwarfs, no matter what mass they were born with. But which stars shed enough mass to reach this limit? One strategy fo...
Chandrasekhar limit: the upper limit to the mass of a white dwarf (equals 1.4 times the mass of the Sun) degenerate gas: a gas that resists further compression because no two electrons can be in the same place at the same time doing the same thing (Pauli exclusion principle)
May 9, 2023 · The big difference between the evolution of the high-mass and lower mass stars, in addition to the core composition, is that in higher mass stars the core quickly becomes too massive (bigger than about 1.2 to 1.3 solar masses) to be supported by electron degeneracy pressure. An instability is triggered by the capture of electrons by nuclei, the core collapses suddenly, which releases the ...
Star Formation: Low-Mass: Low-mass stars like our Sun are formed in dense cores of molecular gas clouds. At optical wavelengths, the star formation process is hidden from view by interstellar dust, and even at infrared wavelengths the most deeply embedded protostars often remain unseen. Since most of the material in dense cores is cold, below ...
Figure 23.4Evolutionary Track for a Star Like the Sun. This diagram shows the changes in luminosity and surface temperature for a star with a mass like the Sun’s as it nears the end of its life. After the star becomes a giant again (point A on the diagram), it will lose more and more mass as its core begins to collapse.
People also ask
Why does a low-mass star collapse?
What happens if a star collapses?
How are low-mass stars formed?
What happened to a star with a mass like the Sun?
What happens when a star becomes a giant?
How does mass loss affect a planetary nebula?
Jan 17, 2021 · Here’s how it works. Stars begin their lives when hydrogen fusion ignites in their dense, hot cores. Once that process starts, it's game on. The gravitational pull of all the mass of the star ...
