[RightWhale]

Everything heavier than helium came from inside stars. Doesn't mean those stars still exist. The one that made the material of earth was probably a supernova, and that star is long gone, blown up. The present sun could have formed at the same time as the planets in the system. The radioisotopes inside earth didn't come from the sun, but were created from the parent star. The sun we have now is immaterial to presence or absence of life.