If memory serves, however...
- A supernova can briefly outshine the rest of the galaxy it is a part of.
- They occur about once every two hundred years per galaxy, and ones within our galaxy (but not too close!) can usually be seen by the naked eye, often even during the day.
- They are the main process in the universe which creates elements heavier than iron, and in fact all the matter heavier than helium in our Solar System was thought to have been formed in a massive star's core, or in it's final supernova.
- They can result in a neutron star, which is the core of the old star compressed under gravity so much that it's matter is almost entirely composed of neutrons, or for larger stars, a black hole.
- The glow which is visible around one for several weeks after the main event is mainly the result of the decay of radioisotopes formed in the cataclysmic blast.
- The escaping outer layers of the former star tend to form planetary nebulae.
- And you don't want to stay too close to one, either.
- It has been calculated that it is likely that at least one supernova has occurred close enough to the Earth to have caused a mass extinction, by dint of bathing the Earth with large amounts of cosmic rays and other radiation.
- It has been theorised that the largest mass extinction in Earth's history was in fact caused by one of these nearby supernovae.
Just my 2c worth... if I still had my
Asimov books, this node would be of better quality. Don't blame me, blame my mum!