The Sun took 30 million years to evolve from a collapsing cloud core to a star, with 10 million of those years spent on its Hayashi track. It will spend a total of 10 billion years on the main sequence. Suppose we were to compress the Sun’s main-sequence lifetime into just a single day.
a) How long would the total collapse phase last?
b) How long would the Sun spend on its Hayashi track?