Questions tagged [stellar-evolution]
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Neutron Star formation Entropy
When a neutron star forms, is its entropy lower than when it was in the form of the star core. In the case of a black hole the entropy becomes the surface area, so what happens in a neutron star ...
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Massive star evolution leading to white dwarf?
Is it possible that a star with an initial mass greater than $12 M_\odot$ loses so much mass in the giant phase that it eventually becomes a white dwarf? If it is possible, what constellation or ...
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Why can we not describe matter as an ideal gas when the gas is degenerate
When a low mass stars core mostly consists of helium (after years and years of fusion reactions) its thermal pressure decreases and so the core gets denser due to gravitational pressure.
Why is it ...
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How fast is the naked-eye visible transition of a main sequence star to a giant? [duplicate]
I know the evolution of a main sequence star to a giant is a process that takes millions and millions of years, but how fast is the VISIBLE change? Basically, will our sun, for example, slowly grow to ...
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Why are black holes sometimes formed without supernovae?
I've heard that very massive stars can sometimes collapse into black holes without creating supernovae.
How does this happen?
(I suspect it's something to do with the relative lack of Urca process ...
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Difference between star formation rate and star formation history
When we speak about galaxies evolution, what is the difference between the star formation rate and the star formation history?
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How many type II supernovae are there per stellar mass formed?
I have been searching for the number of type II (core-collapse) supernovae per unit of stellar mass formed.
It is my understanding that a star must have an initial mass of at least 8 times and no more ...
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Would a black hole instantly form when a neutron star slips below the phantom event horizon?
So lets say we have a neutron star that is just few inches away from the phantom horizon and only needs 500 kg before collapsing. So lets say hypothetically that a ship that is designed to survive the ...
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Why don't less massive stars explode in form of supernovas?
I'm a high school student with a question about supernovas and the life cycle of stars. I understand that supernovas occur in massive stars when they run out of fuel and collapse, resulting in a ...
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Can a massive star become a red giant more than once?
Massive stars may undergo multiple fusion processes as they near the end of their lifespans. Our sun will eventually start fusing helium in its inner core so that carbon is formed. As this occurs, the ...
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Is it possible to tell the difference between a young star that is just "big" and an older red giant?
I read the Wikipedia page for one of the biggest known stars, UY Scuti, and was curious to see the age of the star isn't really known at all.
When a star's hydrogen fuel is exhausted, it starts ...
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Pair-instability supernovae: how does it happen?
How does the formation of electron positron pairs increase the energy density and softens the EOS?
I trrying to understand the pair instability supernova. In many texts and articles, it is written ...
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Why is the common envelope ejected in some accretor-donor systems?
As an example, let us consider a binary system of a neutron star and an evolved star (e.g. red giant) that has expanded, filled its roche lobe, and started the mass transfer onto the neutron star.
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How hot is the core of a star just before it collapses to form a black hole?
Is the core of a star still hot as the star collapses under its own gravity?
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How could have Boson Stars formed in the universe at all?
Boson particles have been predicted by some to have been able to form stars known as Boson Stars. I am curious as to how these stars could have formed given that Boson particles are not truly affected ...
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