Supernova

“The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of starstuff.”

― Carl Sagan, Cosmos

Simplistic view of different stages of stars

Crab Nebula

 Doesn't it feel wonderful to be made up off starstuff. Well today I want talk about a spectacular phenomenon called supernova where most of the massive metals are made. Above is a very simplistic diagram of life cycle of a star. As you can see depending on the mass of the star (roughly if mass is greater than 8 times the mass of sun, it is considered a massive star) it can have different paths. During their life span they burn hydrogen initially to produce the energy. As the time passes, massive elements are formed. In the end they end their life as a supernovae.

 Supernova is an explosion of massive star at the end of its life. It is a very energetic event where energy equivalent to billion times the energy of sun is produced. To get the sense of this amount of energy, the energy consumption of the world for 2008 was about 5*10^20 joules. The energy from one supernova is nearly 10^46 joules.  From this explosion the elements made in star core is distributed in space. These event on average occur only once per galaxy per 100 years. In the universe there are around 30 supernovae per second. This interesting fact gives you idea as to how huge our universe is.