For a star similar to the Sun, what is the approximate duration of the slow contraction stage before fusion takes over?

Answer

50 million years

While the initial collapse can be quick, the subsequent protracted slow contraction stage, where thermal pressure builds toward the fusion threshold, can last for approximately 50 million years for a solar-mass object.

For a star similar to the Sun, what is the approximate duration of the slow contraction stage before fusion takes over?
protostarstellar evolutionstar formationastrophysicscollapse