Is Proxima Centauri the nearest star to the earth or sun?
Proxima centauri is 4.243 light years from Sun.
The difference between Earth and Sun is only 8.2 light minutes.
So it does not matter whether it is Sun or Earth.
The distance 4.243 light years is 2230120 light minutes, In this figure a small difference of 8.2 is very small and is negligible.