Answer
The answers to part (a) and part (b) both increase.
Work Step by Step
We can write an expression for the speed at the equator:
$v = \frac{2\pi~r}{T}$
If the star rotates faster, the period $T$ decreases. Therefore, the speed $v$ increases.
We can write an expression for the acceleration:
$a = \frac{v^2}{r}$
As shown above, if the star rotates faster, the speed $v$ increases. Therefore, the magnitude of the acceleration increases.
