• Question: How does a supernova completely destroy a star?

    Asked by Mason The Amazing :) to Andrew, Hina, Ian, Kathryn, Leah-Nani, Xu on 14 Jun 2018.
    • Photo: Kathryn Burrows

      Kathryn Burrows answered on 14 Jun 2018:


      In my understanding at some stage in a stars life a chain reaction may form which ends in an explosion which blasts away most of the matter from a star. We see a large burst of light [many years later when it has travelled all the way to the Earth] which we call a supernova. Not all of the star is gone though and the remainder can in fact be denser than the original star, forming a neutron star or black hole.

      Check this picture out:

    • Photo: Andrew Margetts-Kelly

      Andrew Margetts-Kelly answered on 15 Jun 2018:


      There is almost always something left afterwards; whether that be a black hole, a neutron star or a dwarf remnant of the star that was there before.

      However, there is an “almost always”. When the star has just the right amount of heavy elements in and is of just the right mass a supernova (or even a hypernova) can lead to absolutely no remnant (nothing left). This happens because when the core collapses it reignites but this time fusing oxygen instead of lighter elements. When the mass of the star is in a Goldilocks region (not too small and not too big) there is just the right amount of energy released by this new fusion to eject all the material from the core, leaving nothing behind.

      You can think of it like dropping a tennis ball from the roof of your school into the playground, it’ll bounce back but not all the way back. If your mate is in the playground with a cricket bat called oxygen fusion and they hit the ball really really really hard, the ball is disappear off into the field. This is kind of how a collapsing star can cause itself to completely obliterate itself.

Comments