What is the approximate core temperature required for helium fusion, known as helium ignition, to begin?

Answer

100 million Kelvin ($ ext{10}^8 ext{ K}$)

Helium fusion, specifically the triple-alpha process, requires the core temperature to reach approximately 100 million Kelvin ($ ext{10}^8 ext{ K}$) after hydrogen fuel has been depleted.

What is the approximate core temperature required for helium fusion, known as helium ignition, to begin?
ElementstarastrophysicsFusionnucleosynthesis