Why is mass important for a supernova?

Answer 1

Stars produce energy through nuclear fusion, producing heavier elements from lighter ones. The heat generated by these reactions prevents gravitational collapse of the star. The star builds up a central core which consists of elements, where the temperature at the centre of the star is not sufficient to fuse them. For main sequence stars with a mass less than about 8 Suns, the mass of the core will eventually lose mass as planetary nebulae until only the core remains. Which becomes a white dwarf.

Stars with higher mass will develop a degenerate core where the mass will grow until it exceeds the Chandrasekhar limit [See Link]. At this point the star will explode in a core collapse supernova, leaving behind either a neutron star or a black hole.

For Type II supernova [See Link] [See related] mass flows into the core by the continued making of iron from nuclear fusion. Once the core has gained so much mass that it cannot withstand its own weight, the core implodes. This implosion can usually be halted by neutrons (the only things that can stop a gravitational collapse). When the mass of the star is so great even neutrons fail. The collapse is abruptly stopped by the neutrons, matter bounces off the hard iron core, and turns the implosion into an explosion.

For Type Ia supernova, [See Link] [See related] the energy comes from the runaway fusion of carbon and oxygen in the core of the white dwarf.