What period defines the time between initial gravitational collapse and the onset of stable nuclear fusion?
Answer
The protostar phase
The protostar phase is specifically defined as the duration during which the object is actively contracting and gathering mass but has not yet achieved the sustained nuclear fusion necessary to maintain hydrostatic equilibrium as a true star.
Frequently Asked Questions
What period defines the time between initial gravitational collapse and the onset of stable nuclear fusion?What energy conversion is fundamental during the initial rapid gravitational collapse?Why does the initial collapse proceed unimpeded by thermal pressure in the very early stages?What mechanism allows a protostar to achieve a temporary, intermediate equilibrium before fusion begins?What physical change causes the free-fall contraction to slow dramatically into the Kelvin-Helmholtz phase?What role does material opacity play in accelerating internal heat buildup?What is the critical temperature required for hydrogen nuclei to overcome electrostatic repulsion and initiate fusion in a Sun-like star?Before fusion dominates, what mechanism supplies the energy output of a contracting protostar?Which characteristic activity distinguishes the turbulent protostar stage from a stable main-sequence star?For a star similar to the Sun, what is the approximate duration of the slow contraction stage before fusion takes over?