hydrogen and helium burning |
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
PPI chain | PPII chain | PPIII chain |
this starts with reactions 1 and 2 | this starts with reactions 1, 2 and 3' | |
1
p + p -->
d + e+ + ![]() |
3'
3He + 4He -->
7Be + ![]() |
4''
7Be + p -->
8B + ![]() |
2
d + p -->
3He + ![]() |
4'
7Be + e- -->
7Li + ![]() |
5''
8B -->
8Be + e+ +
![]() |
3 3He + 3He --> 4He + p + p | 5' 7Li + p --> 4He + 4He | 6'' 8Be --> 4He + 4He |
Figure 17: |
The proton-proton chain.
|
1 12C + p
--> 13N + ![]() |
2 13N
--> 13C + e+ +
![]() |
3 13C + p
--> 14N + ![]() |
4 14N + p
--> 15O + ![]() |
5 15O
--> 15N + e+ +
![]() |
6 15N + p --> 12C + 4He |
Figure 18: |
The CNO cycle.
|
4He + 4He --> 8Be |
8Be +
4He -->
12C + ![]() |
Figure 19: |
The triple alpha reaction.
|