Supernova and Blackholes

Two astronomical objects that have a very different life and a very different end of life are supernova blackhole. The supernova is a star with small mass that may eventually explode. A blackhole has a different astronomical life; it becomes a gravitational object on its own, which defies the ordinary laws of physics.

A supernova is a star that explodes. It explodes because the star has layers of different elements and it is reacting to the nuclear processes involved with those elements. The outer layers contain hydrogen, helium, carbon, and silicon and are burning around the iron core, adding to it and making it more massive. But at the same time, as the core grows in mass, eventually the massive iron core succumbs, due to its own gravity, and it collapses to form a neutron star. The outer layers of the star fall in and compress on themselves. Then, they bounce off the neutron core which creates a shock wave that blows the outer layer outward. What you now have is the supernova explosion.

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_{Source: http://jcconwell.files.wordpress.com/2009/07/supernova.jpg}

A black hole is a collapsed star whose gravitational field is so strong that even light cannot escape it's pull. In other words, if you shined a light on a black hole you would not get a reflection back. It is so massive that nearby objects cannot escape its gravitational pull.

A black hole is the theoretical prediction of Einstein's General Theory of Relativity. There are two main parts to the Black hole, one is known as the event horizon, the region that separates the real world space-time from the inside of the black hole. The second part is the singularity, which is the compressed effect of the object.

A black hole is usually considered to be at the center of each galaxy.

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_{Source: http://faraday.fc.up.pt/cfp/Members/paccetti/black_hole_milkyway.jpg}

The mass structure of large objects determines what the astronomical life cycle of the object will be. For instance, consider our Sun. If a stellar object has the equivalent mass to our Sun, it could collapse into a white dwarf. If the object is up to 3 times as massive, it could compact into a neutron star. But if it is more than 3 times as massive, it will collapse into a Black Hole.

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_{Source: http://imagine.gsfc.nasa.gov/docs/science/know_l1/supernovae.html}

Why the collapse?

While a star is burning, it counterbalances the effect of gravity. Stars have a lot of mass, and they are not solid, but gaseous, so to prevent a star from collapsing onto itself, the burning energy provides a counter force to gravity. However, a star will eventually burn itself out and the effect of gravity will take over. So, if the remnants of the star are as massive as our Sun, a white dwarf forms, more massive, and a neutron star forms, and greater than 3 times as massive, a Black Hole forms.

When is there a Supernova explosion?

The process that burns the gas on a star, the nuclear process, however, is not tidy. Young stars are made up largely of hydrogen, and the nuclear fusion reactions converts the hydrogen (1 proton, 1 electron, 0 neutrons) into helium (2 protons, 2 electrons, 2 neutrons) with heat and light energy left over. As the process continues, most of the hydrogen will be converted to helium, and a new nuclear reaction begins which converts the helium to carbon (6,6,6), with the left over energy radiation. This process continues converting the carbon to oxygen (8,8,8) to silicon (14,14,14) to iron (26,26,30). Nuclear fusion ends at iron.

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Two radically different astronomical objects supernova, blackhole respond to the mass that they contain. Smaller mass objects, that is smaller than the Sun, will result in white dwarf's, which could eventually explode into a supernova. The larger more massive stars with a mass that is three to four times as massive as our Sun have the potential of becoming black holes.