SUPERNOVA

Supernova is the explosion of a star in the galaxy that emits more energy than nova. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months. In the end of star life,the star will cause supernova. But not all star will have supernova, just star that have more than 8 times mass of sun (=>8Msun). Sun mass is 1.99 x 10³⁰ kg. After supernova,the next step of star evolution is become neutron star(star initial mass<=8Msun) or black hole(star initial mass=>8Msun).

Image of Supernova

Cassiopeia A Supernova

Based on spectral lines in supernovae, we can found several types of supernovae

1.Supernova type I
This type can found on elips galaxy,the old galaxy that have old stars in majority. Supernova I is weaker than supernova type II.Supernova type could divided again as :

a.    Supernova Ia    => there is hydrogen  spectrum line

b.    Supernova Ib/c  => there is no hydrogen or helium spectrum line
2.Supernova type II

When observation, we can found Hidrogen line on this supernova type. Generally,supernova type II happen in young galaxy,like spiral galaxy that contains young stars.

Step of supernova

1.    Swelling

Star swelling because it send his Helium core to the ouside layer. Star will become red giant star as the swelling. It will become brighter (luminosity increase),the color become red, but its temperature will decrease. The mass become heavier than before.

2.    Iron(Fe) core forming

Because the hydrogen as the main energy source from nuclear fussion reaction was run out,iron will be produced on the core.

3.    Explosion

The star’s core temperature increase until 100billion°C. Then this energy will transfered to outside and explode,create shock wave .This explosion will create new elements cause of the material from explosion fused.

Supernovae have implications for life beyond the stars, among them:
Produces Metal
1. At the core of stars, nuclear fusion reaction occurs. In this reaction born elementsheavier than Hydrogen and Helium. When that happens, these elements are thrown outthe stars and enrich the surrounding interstellar cloud with heavy elements.

2. Creating Life in the Universe
Supernova catapult certain elements into space. These elements are then transferred to other parts far from the exploded star. It is assumed that the element or material is thenjoined to form a new star or even a planet in the universe.


Source : http://en.wikipedia.org/wiki/Supernova