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physical phenomena > energy source > exothermic fusion process > helium burning > helium shell flash

helium shell flash
subject			fact

helium shell flash	has definition It has been shown that helium shell burning outside a degenerate core is unstable; the helium-burning shell does not generate energy at a constant rate but instead produces energy primarily during short flashes. During a flash, the region just outside the helium-burning shell becomes unstable to convection. The resultant mixing probably leads to the s-process as well as to the upward movement of carbon produced by helium burning.
	is a kind of helium burning
helium burning	has duration 5 × 105 years
	has optimum density 700 g/cm3
	requires minimum mass at star birth 0.5 solar masses
	has optimum temperature 2 × 108 K
	has part product carbon
	has next higher temperature reaction carbon burning
	has product carbon, oxygen
	has reactant helium
exothermic fusion process	liberates energy
fusion	has antonym fission
	produces energy
	has reaction probability
	has catalyst
	has minimum temperature
physical process	has domain physics

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