Question

A star is moving towards the earth with a speed at 90% the speed of light. It emits light, which moves away from the star at the speed of light. Relative to us on earth, what is the speed of the light moving toward us from the star?

Answer 1

The speed of light measured in any frame is c = 3.00E8 m/s.

This is one of Einstein's postulates of special relativity.