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Questions tagged [red-supergiant]

Questions regarding very large, cool evolved stars with high luminosity, size, and mass loss.

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22 votes
1 answer
2k views

Are stars expected to become dimmer before a supernova?

With the recent news about the "fainting" of Betelgeuse and the speculation that this might be a precursor to a supernova, I'm wondering if there is any theoretical/observational basis for this ...
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11 votes
1 answer
195 views

Does the dimming of Betelgeuse present any observational opportunities?

Recent photometry suggests that Betelgeuse has been dimming over the past three or so months, reaching the faintest V-band magnitude seen in modern observations. The changes are apparently even ...
HDE 226868's user avatar
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8 votes
1 answer
656 views

What would the effects on or around Earth if Betelgeuse went supernova?

There's been a lot of news lately about Betelgeuse possibly exploding sooner than perhaps was expected. Some examples: Guinan, Edward F.; Wasatonic, Richard J.; Calderwood, Thomas J. (8 December 2019)...
jvriesem's user avatar
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6 votes
2 answers
252 views

Are any supergiants translucent?

Are any supergiants translucent? Some have volumes thousands of times more than the Sun's while having maybe twenty times the mass of the Sun which makes them sound rather diffuse. If there was a very ...
Some Student's user avatar
3 votes
2 answers
324 views

Which star has the highest mass loss rate?

We have known lists of stars with high luminosity, temperature, mass, size, and much more. However, I have not seen a list that compares each star's mass loss rates. So, which star (or stars) have the ...
WarpPrime's user avatar
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3 votes
1 answer
143 views

At what distance could a supernova damage the Earth's ozone layer?

As from my latter question it seems Betelgeuse might be much closer than the usually presumed 640 light years. It might be as close as ~440 ly. Suppose it is, would this have any dangerous effects on ...
Ioannes's user avatar
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2 votes
2 answers
290 views

How can red supergiants be cooler than dwarfs of the same spectral type?

The Stellar Classification Wikipedia article has a sentence: Red supergiants are cooler and redder than dwarfs of the same spectral type Which seems to be true, my course has a similar statement. ...
zabop's user avatar
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2 votes
2 answers
186 views

How to accurately measure the temperature of red supergiants?

I just (February 28th, 2021) heard the news on progress how to measure the temperature of super giants: Red supergiants are a class of star that end their lives in supernova explosions. Their ...
B--rian's user avatar
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2 votes
1 answer
83 views

What criteria determines whether stars are supernova type II candidates?

I want to find supernova candidates by using the Gaia catalog in 300 parsec (near Earth). I though they must be red super giants so they are cooler than 4100 K and more luminous than 104 solar ...
Aegean's user avatar
  • 109
2 votes
1 answer
162 views

Can a Thorne-Żytkow object be the progenitor of a modern quasi-star?

I was reading some Wikipedia articles about astronomy, and came across an interesting line: The neutron star may also accrete sufficient material to collapse into a black hole. Now, here is my ...
slowerthanstopped's user avatar
2 votes
0 answers
70 views

Which star has the highest estimated mass-loss rate? [duplicate]

As far as I know, stars like RSGs and LBVs have the highest mass loss rates. There is Eta Carinae (0.00039 solar masses/yr), NML Cygni (0.00042 - 0.00048 solar masses/yr), WOH G64 (0.00072 solar ...
Migmanychion's user avatar
2 votes
0 answers
68 views

How big could a regular star in supergiant/hypergiant phase theoretically get, not counting quasi-stars?

For clarity, I'm not asking about the super-behemoths that are quasi-stars. I'm interested in knowing how large a regular star could theoretically get once it reached supergiant/hypergiant phase, ...
zucculent's user avatar
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0 votes
0 answers
62 views

Red supergiants with luminosities significantly above the Humphreys-Davidson limit?

The M33 red supergiants (RSDs) LGGS J013312.26+310053.3 and LGGS J013339.28+303118.8 both have luminosities significantly above the Humphreys-Davidson (HD) limit (logL 5.76 and 5.68 [source], ...
Migmanychion's user avatar