The energy to produce a thermal pulse comes from:

Question

Quizplus · Accepted Answer

A thermal pulse occurs during the asymptotic giant branch (AGB) phase of a star's evolution, when the helium shell around the core ignites explosively. This release of energy creates a shell of hot gas that expands outward, causing the star's outer envelope to expand and cool. The energy for this process comes from the gravitational energy stored in the core as it contracts and heats up, which triggers the helium shell flash. Therefore, the correct choice is D - the helium shell flash.

The Energy to Produce a Thermal Pulse Comes From