stars part 2

This is the final part of the stars subject. This is about star deaths. When a star runs out of hydrogen, its starts burning helium and keeps burning heavier elements until it reaches iron. As soon as it gets to iron, the stars cannot withstand its own weight and it starts to collapse. A star can burn for anything from 1 trillion years, a really small star to a million years, a massive star. A low mass star will just fizzle out and turn into a black dwarf. A sun like star will grow to 100 times it's mass and then shrink and form a white dwarf. The red giant which is the bit where the sun expands will burn mercury,Venus and possibly Earth and mars. A high mass stars will explode as a supernova or even bigger, a hypernova, and then collapse into a proton star or a neutron star or a black hole. Sometimes a star refuses to collapse and resists it, but it explodes and a gamma ray burst out as it explodes. A gamma ray could easily cause mass extinction or even wipe out all life! Of course this gamma ray would have to be 100 light years away and there is no big enough star to cause one. A supergiant is the expanded high mass star but a hypergiant is a star and not a remnant  of a dieing star. Well that's it, good bye and tune in tomorrow

Kelper's supernova