All Questions
11
questions
10
votes
2
answers
5k
views
Why does nuclear fusion generate heat?
I understand that nuclear fusion generates energy in the form of gamma-rays (as in the pp chain), but how does that translate into heat in the star's core? Or is the heat just generated by ...
- 733
2
votes
1
answer
219
views
Pure Lithium Star
Suppose by some miracle a large molecular cloud of pure lithium assembled itself in space, then gravitationally collapsed.
What would the result look like? Would it be a star of some sort (fusing the ...
- 129
0
votes
2
answers
91
views
Does most of the Sun's energy and light come from its black-body temperature, due to its massive size alone? Constant crashing of particles?
Stars have to be a certain size to initiate fusion to begin with, correct?
Isn't this why brown dwarfs are considered 'failed stars'?
But wouldn't the Sun (and other stars with sufficient mass, like ...
- 5,177
2
votes
1
answer
91
views
Is there a way to compare input and output energy of solar fusion to the input and output energy of man made fusion?
The Livermore fusion experiment was said to be 2 megajoules of energy in and 3 megajoules of energy out. However upon closer inspection the facility used 300 megajoules of energy. So man made uses 300 ...
- 1,201
1
vote
1
answer
155
views
Bremsstrahlung's role in the sun
Due to nuclear fusion that produces gamma rays which goes through compton scattering, in the end, on the surface, visible, infrared light ends up as before then, gamma rays lost energy and became x-...
- 315
4
votes
1
answer
79
views
How does carbon end up in the remnants
We know that one way carbon ends up in the interstellar medium which by the way is one or the heavy elements that help form the planet.
But we also know that in the core, carbons fuse with another ...
- 315
4
votes
2
answers
200
views
Do brown dwarf 'stars' fuse simple hydrogen (p-p reaction) at all?
I sometimes read that only deuterium-deuterium fusion can occur in brown dwarfs... And maybe deuterium-proton fusion? To He-3?
In order to overcome Coulombic repulsion and, occasionally, fuse, protons ...
- 5,177
6
votes
3
answers
354
views
In layman's terms, why does the cold C-N-O process end in Carbon?
I read up a little bit on fusion in stars, layman's articles only and the P-P chain makes hydrogen or Alpha particles. (error removed on triple-alpha), then the C-N-O process adds hydrogen to the ...
- 24.1k
8
votes
1
answer
1k
views
What is it like to see a brown dwarf turn into a star?
Brown dwarfs/failed stars can actually become stars, if they exceed a mass limit of about 80 Jupiter masses. This is when the internal pressure and temperature at the core become high enough to ...
- 2,668
17
votes
1
answer
676
views
Is stellar ignition all-or-nothing?
The boundary between brown dwarfs and stars is around 80 Jupiter masses. Only stars generate a self-sustaining hydrogen fusion, although brown dwarfs sometimes fuse lithium and deuterium.
Is hydrogen ...
- 920
4
votes
1
answer
681
views
Why do stars usually stop fusion at iron, even though nickel-62 has the highest binding energy per nucleon?
We know that iron is often regarded as 'nuclear ash' because of its inability to fuse with other atoms, as it has a high binding energy per nucleon. However I found that Nickel-62, grabs the title of ...
- 385