Questions tagged [red-giant]

Questions about red giants, large luminous low-mass stars in a late phase of stellar evolution.

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Source of information on density profile of a red giant star?

Is there a good source of information of the expected density profile inside a red giant star? I have read that when a star such as the sun has converted much or most of the hydrogen in its core into ...
PAUL MILENKOVIC's user avatar
3 votes
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How can I calculate evolutionary timescales of low mass stars?

How can I calculate how long a star of a given mass will spend on an evolutionary branch before evolving off it? I'm thinking about the evolution of low mass stars from the subgiant branch to the red ...
Holly Bee's user avatar
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Are there any binary red supergiants?

I wonder if we ever have identified or observed a pair of binary stars (red supergiants). And I also wonder what would happen if they exploded, (theoretically) as we haven’t observed it. Also, would ...
schrodingerscat's user avatar
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What is the theoretical maximum variability a pulsating red giant can have such that a habitable planet can stay habitable for long periods of time?

I was reading about red giants and came across this statement: Some research suggests that, during the evolution of a 1 M☉ star along the red-giant branch, it could harbor a habitable zone for ...
fasterthanlight's user avatar
2 votes
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Dynamics of red giant hydrogen shell

From what I understood from this answer to How can a red giant grow so big? But this is not at all the way the shell fusing in a red giant self-regulates its fusion rate-- it cannot regulate its ...
Passer By's user avatar
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Jupiter/Saturn's fate after Sun goes red giant and planetary nebula?

The solar wind contributes a very small amount of matter to the gas giants. As the sun approaches the red giant phase, the solar wind increases significantly. 10% of the sun's mass lost as solar ...
Brooks Nelson's user avatar
1 vote
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Why red giants have cooler surface than MS stars?

I know that with increasing age and depletion of hydrogen in the core the radiation inside a main sequence (MS) star increases pushing the envelope/surface of the star outwards. What I don't ...
NeStack's user avatar
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Is a star with 2/3 solar masses and 9/10 solar radii still in the main sequence?

As far as I know, K-type and G-type stars (among others) grow in radius as they age, eventually leading to red giant phases. My question is, would a star that is about 0.66 solar masses and 0.94 solar ...
Xi-K's user avatar
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Relation between initial mass and evolutionary phases lifetimes

Consider the following image (Source: An Introduction to Modern Astrophysics): There seems to be a relation between the initial mass/mass at the beginning of the MS and the time spent during ...
Hrsht's user avatar
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Could the Sun's planetary nebula be dangerous for the planets?

Since the Sun's mass isn't high enough it won't go supernova being a red giant but instead release a planetary nebula. So that seems to be kind of a substitute for a supernova. Would ejecting the ...
user30007's user avatar
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