how is the black hole formed? – Extreme Size Zone

Question: how is the black hole formed?
- Keywords:
  black hole,
  space,
  universe
Asked by kaylee222 to Nick, Francesca, Deepak, Alan on 11 Mar 2014. This question was also asked by gunna, .
- Alan Fitzsimmons answered on 11 Mar 2014:
  
  We think black holes are created when very large stars die. Some stars are 50 times the weight of the Sun or more, and when they die they explode. In the middle of the explosion the centre of the star becomes a black hole.
  
  The good news is that our Sun is far too small to make a black whole, and when it dies in 5 billion years there will be no explosion. It might still destroy the Earth though!
- Francesca Day answered on 11 Mar 2014:
  
  That’s a very interesting question! Black holes are created when there is so much stuff squashed into a very small space that even light can’t escape its gravity. This happens when very big stars die. The explosion they create is so powerful that the centre of the star is squashed into a black hole.
- Nick Wright answered on 11 Mar 2014:
  
  We think that black holes are created when stars become so heavy that they cannot support their own weight and their outer atmospheres collapse down onto the centres of the stars making something so dense and compact that nothing can escape its gravitational pull.

Question: how is the black hole formed?