Introduction Deep in the vastness of space, beyond our solar system, stars are born in primordial nebulae, gaseous molecular clouds on the spiral arms of galaxies extending across the heavens. Intense gravitational forces compress the cloud causing temperature and pressure to increase immensely. At critical temperatures and pressures within the nebula the miracle of life occurs. Thermonuclear reactions erupt violently fusing hydrogen to helium. Within this gaseous womb a protostar is born, and just as there is new life in the universe there is also death… Fueled by nuclear reactions the star lives a solitary life emitting it’s light into the blackness of space for millions of years. For those stars smaller than 1.4 suns they will die a peaceful death as there nuclear fuel is exhausted and their core balances out against gravity’s compressive force via electron degeneracy pressure becoming a white dwarf star. After billions of years, a white dwarf's thermal energy will be exhausted and it radiates its final glow as it dies becoming a non-luminous black dwarf. What is the fate of a star greater than 1.4 suns? It will not settle into a white dwarf, and eventually become a black dwarf. Will it be able to balance out against the force of gravity? A much more violent death awaits those massive stars. Massive Stars For stars much greater than 1.4 suns death is violent and chaotic. Massive stars burn much hotter and brighter than the smaller stars that enter the stellar graveyard as black dwarfs. In the core of these massive stars nuclear forces acting over minute distances on the order of 10-13 cm cause intense nuclear fusion reactions. The nuclei of these elements within the core of the star electrically repel each other. Extremely high temperatures are needed to overcome this repulsion and these high temperatures along with extreme internal pressures provide the energy needed to ignite nuclear reactions. These massive stars are powered by a sequence of nuclear reactions that produce heavier and heavier elements. As the nuclear fuel is exhausted heavier elements are produced; hydrogen fuses with helium, helium fuses with carbon and oxygen, then carbon and oxygen fuses with neon and magnesium, this is followed by fusion of those elements into silicon and sulfur. Each fusion cycle releases energy that balances against the inward compression of the star due to the gravitational force. However as this nuclear fuel is used it settles down into a state where fusion can no longer occur. The final remnants of the last fusion cycle are iron. However no nuclear reaction can release energy from the iron, signaling the end of the road for the massive star. Without the energy of nuclear fusion reactions the star cannot balance its outward force caused by the nuclear reactions with the inward directed force of gravity. The massive star now has an iron core that exceeds Chandrasekhar’s limit of 1.4 suns, the star cannot reach equilibrium as the white dwarf did. There is no nuclear fuel left to burn. Gravity attacks, the star shudders and the core collapses in a catastrophic event as it reaches the density of an atomic nucleus about a million billion times the density of water. The nuclei are ripped apart so that a soup of densely packed particles remains. This collapse releases energy that is equivalent to ten times the output energy of the star during its entire lifetime. The density increases more and more and gravity’s inward compression becomes so great that the protons and electrons are fused together forming neutrons. Under normal circumstances a free neutron would decay in to a proton via the exchange of an intermediate vector boson that decays into an electron and an anti-electron neutrino. This process is commonly called beta decay. However gravity’s crushing hold will not allow this. The density is so great and the neutrons are packed so tightly that the Pauli Exclusion Principle will not allow any electrons to be create during the decay of a neutron into a proton. The core is now tightly packed with about 1057 neutrons. A single thimble full of a neutron stars material would weigh nearly 100 million tons. The energy used up in the collapse of the core is only about 10% of the total energy being supplied by gravity. The other 90% of the energy leaves in the form of a massive explosion called a supernova. Supernovae A core collapse supernova occurs when the stars collapses inward due to the gravitational force and the energy rebounds off the core and blows the outer layers of the star into space causing a massive explosion. About 90% of the energy of the supernova is carried away from the star by subatomic particles called neutrinos. These neutrinos are formed when a proton fuses with an electron. During the rapid collapse of the star intense energies cause the nuclei to be spilt into its elementary particle components, electrons protons and neutrons. The collapse accelerates causing the fusion of protons with electrons which intern releases the neutrinos that are observed during supernovae explosions. This process is called the neutronization of the core. These neutrinos rarely interact with matter and are extremely lightweight particles. The remaining energy rebounds of the newly formed neutron core and radiates outward. This other 10% of the energy of the supernovae triggers the massive explosion that blows off the layers of the star. On February 23, 1987 supernova 1987A was observed a mere 170,000 light years away in the Large Magellanic Cloud. The significance of this supernova was that it was the first time a star had been observed before and after the supernova explosion. The star was on the order of 20 solar masses. The observations made by scientists largely agreed with the theoretical predictions of supernova theory at the time. One such successful prediction was the observation of neutrinos at the Kamiokande II detector in Japan and the IMB detector in Cleveland Ohio. Both of these detectors registered neutrinos a few hours before optical telescopes could observe the shock wave erupt over the star’s surface. This neutrino burst lasted for approximately one minute. That event marked the first detection of neutrinos from and astronomical body. On that day it is estimated that about 100 trillion neutrinos from supernova 1987A passed through each persons body maybe even reacting with a nuclei inside you. The star explodes sending debris hurling into interstellar space. But is the violent supernova the final death of the star, what remains after the explosion? A small ultra-compressed high-density core remains; it is called a neutron star.