Question

Jupiter has a similar composition to the sun. Why is the sun a star while Jupiter is not?

Answer 1

The correct answer is (b) Jupiter has mass less than that of sun which cannot generate enough pressure which can start hydrogen fusion. Jupiter has similar composition as both are entirely made up of hydrogen and helium. They both differ in the core and mass. The mass of Jupiter is so small as compared that it would not be able to generate enough pressure to start hydrogen fusion. Jupiter's core is made of metallic hydrogen and the core of sun is so hot that the hydrogen splits into electrons and protons. This generates hydrogen fusion.

Thus, Sun a star and Jupiter is not a star.