Research Related to an Amazing Phenomenon: a Supernova
When you look up into the sky you see millions of bright shinnying stars. Stars are similar to people, they are born, live their lives and then die. Stars are formed in clouds of dust and gas called nebula. Particles inside the nebula collide and clump together to form stars. When material has accumulated the pressure and temperature in the core exceeds the threshold and fu ion begins. A star is born. Nuclear reactions at the core of the stars provide enough energy to make the star shine bright many years. The lifetime of a star depends on the size of the star. Smaller stars can live many billions of years compared to bigger stars that only live a few million years. A larger star will burn its fuel faster than a smaller one. Once the star has gone through its life cycle it eventually ends their lives. This end of life is called supernova.
A supernova is when a star explodes. Supernova is the death of a star and it undergoes five stages. The first stage happens just before the explosion, when a red super-giant star approaches the end of its life when there is no more fuel to burn or make it shine. The core collapses under its own weight. The second stage is the first light flash. The core of the star collapses and sends a shock wave out, for a few hours the shock compresses and heats the stars envelope. This produces a very bright flash of light from the inside of the star. The third stage is when the flash has disappeared. After the shock wave hits the surface at about 50 million km/h the shock blows the star apart. The stars core turns into a neutron star, a compact atomic nucleus with the mass of the Sun. The fourth stage is when the proper Supernova is formed. The hot surface expands quickly making the fireball bright again and in a couple of days it will be ten times the size of the original star. At this stage is where the supernova is discovered. In the final stage the remains of the former star are spread over light years of space. The remains float quickly, sweeping up gas leaving a faint glow behind.
There are two types of supernovas type I and type 2. Type I supernova result from the transfer of mass within a binary system (two stars revolving around each other) that is made up of a white dwarf star and an evolving giant star. Type I can be subdivided into two subgroups Ia and Ib based on the spectra it emits. Ia supernovae originated in binary system consisting of a white dwarf and a massive star. This is the final stage of life for old low-mass stars. When the white dwarf orbits around a larger star, both move close enough that gas and matter from the star transfers to the white dwarf. The increased mass and gravity caused the white dwarf to become unstable and collapses. This collapse releases large amounts of energy and the star matter blasts outward in a supernova explosion. When the explosion occurs it can be so bright that it can outshine other galaxies near it. The remains of the explosion crash inward and can form a black hole.
Type II supernova are huge single stars that complete their life cycle and die a dramatic way. When these types of stars are young they generate energy from the conversion of hydrogen to helium. Through out the stars life cycle the star ages and the hydrogen depletes. The core contracts under pressure of gravity and raises its temperature to burn helium as fuel.
Scientists studying supernovas have learned lots of new information pertaining to the universe. The supernovas involving white dwarfs are used to measure the distances in space. Scientists have also learned that stars generate chemical elements that are needed to make everything in the universe. For example in the stars core hydrogen is converted into heavier elements, such as carbon and nitrogen. The massive stars make heavier elements such as gold, silver and uranium. Scientist use different types of telescopes to search and study supernovas such as NuSTAR which stands for Nuclear Spectroscopic Telescope Array. This type of telescope uses X-ray vision to investigate the universe and helps scientists learn more about what happens during and after during the blast.
Supernovas are not quite common. Astronomers believe that about two to three supernovas occur each century in galaxies. The universe contains many galaxies that astronomers observe a few hundred supernovas per year. Although there have been several civilizations that have recorded supernova before the use of the telescope. According to NASA the oldest supernova recorded was in A.D.185 seen by Chinese astronomers. The most famous supernova named Crab Nebula was recorded in 1054 by Chinese and Korean astronomers. The supernova spotted in 2016 named SN2016aps in a galaxy about 4.6 billion years away radiated about 5 sexdecillion ergs of energy. This supernova was spotting using the Panoramic Survey Telescopes and Rapid Response System located at the Haleakala Observatory in Hawaii. The discovered supernova was measured using two scales. The two scales used were the total energy of the explosion and the radiation. This supernova radiated five times the explosion energy of a typical supernova. The light emitted is about twice the amount of radiation emitted by the previous record holder. At its brightest this supernova was as bright as the stars in the Milky Way.
Supernovas not only are an amazing phenomenon but have also educated scientists and astronomers. They have provided useful information to what chemical elements are produced in the core of stars. These chemical elements are used in everything in the universe.
