Nuclear Burning Lecture Notes

6 from hkt shows reaction rates note that deuterium

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Unformatted text preview: + 8 Be + e+ + ⇥e 4 He + 4 He (15) (16) (17) 8 Figure 6.6 from HKT - shows reaction rates. Note that deuterium and lithium rates are higher than the others - this is why they can proceed in low-mass stars. Deuterium burns when T & 106 K. Lithium also burns readily: T & 3 ⇥ 106 K. 1st PP reaction requires ⌅ 107 February 13, 2014 ASTR 5420 K. Proton- Proton chain •  1st reacOon is the rate- limiOng step, energy generaOon is based on this. February 13, 2014 ASTR 5420 CNO Cycle February 13, 2014 ASTR 5420 CNO Cycle February 13, 2014 ASTR 5420 Energy ProducOon Rates Hansen, Kawaler, Trimble February 13, 2014 ASTR 5420 Main Sequence Phase •  Hydrogen burning •  Begins when temperatures in the core get high enough for hydrogen fusion •  Ends when hydrogen in the core runs out •  What happens aWer MS phase depends on stellar mass… TO BE CONTINUED February 13, 2014 ASTR 5420 Helium...
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