Protostars initially do not experience hydrogen fusion. How does their temperature increase?
A) the light from nearby stars
B) gravitational energy from infalling material
C) fusion of hydrogen into helium
D) energy from their magnetic fields

Question

Quizplus · Accepted Answer

The temperature of protostars increases due to the gravitational energy released as material falls inward and compresses the core, not from hydrogen fusion, which starts later.

Protostars Initially Do Not Experience Hydrogen Fusion