Approximately what temperature must the helium core reach for the triple-alpha process to begin?
Answer
$100$ million Kelvin ($10^8$ K).
The initiation of helium fusion, known specifically as the triple-alpha process, requires extreme core conditions. Helium nuclei possess a strong positive electrical charge, resulting in significant mutual electrical repulsion that must be overcome for them to fuse. To overcome this Coulomb barrier, the kinetic energy of the helium nuclei must be exceptionally high, requiring the core temperature to climb to approximately $100$ million Kelvin. Only when this phenomenal temperature is achieved can three helium nuclei fuse together to form carbon, marking the critical transition point for the star's survival.
Related Questions
What event initiates the transition into the red giant phase for a Sun-like star?What composition characterizes the inert core during the initial red giant expansion phase?What process drives the massive bloating of the star into a red giant?What characteristic defines electron degeneracy pressure supporting the helium core?Approximately what temperature must the helium core reach for the triple-alpha process to begin?What elements are primarily formed during the triple-alpha process in the helium core?Why does the helium flash occur in stars around one solar mass?What evolutionary stage follows helium core ignition stabilization off the Red Giant Branch (RGB)?What is the layered structure of an Asymptotic Giant Branch (AGB) star core post-helium exhaustion?When the Sun expands as a red giant, which inner planet's orbit is predicted to be surpassed?