What is a helium flash?
A) The sudden onset of helium fusion in the core of a low-mass star
B) The ignition of helium shell burning in a high-mass star with a carbon core
C) A sudden brightening of a low-mass star, detectable from Earth by observing spectral lines of helium
D) It is another name for the helium fusion reaction.

Question

Quizplus · Accepted Answer

A helium flash is the sudden onset of helium fusion in the core of a low-mass star. It occurs when the core temperature of a red giant star becomes hot enough for helium fusion to begin, triggering a runaway fusion reaction. This releases a huge amount of energy and causes the star's outer layers to expand and cool.

What Is a Helium Flash