Stars, one of the things that have helped to guide men and women to their destination, they have intrigued expert astronomers or amateur stargazers alike, their presence in ancient times invoked many superstitious beliefs such as the zodiac, lucky stars or even fake gods. Although men have gazed upon stars for hundreds of years, how many of us truly know what these blinking lights in the sky are? Firstly, stars are basically, gargantuan spheres of hydrogen, helium and other gases burning millions of kilometers away in space. Some reside in our very own milky way while others reside in other galaxies. There are six main types of stars, the first being a main sequence star or yellow dwarfs much like our very own sun. Main sequence stars tend to burn for longer periods that is to say billions of years. Blue giants are stars that have much more gas compacted into it much more tightly, thus giving of much more heat and having a bluish appearance because of the temperature. Blue giants tend to live shorter but brighter lives as they burn out their hydrogen extremely fast (relatively on a universal scale), when a blue giant runs out of hydrogen it begins to perform nuclear reactions with helium and grow much larger into a red supergiant, this is also true for main sequence stars.
When the supply of helium runs out, the blue giant begins to implode on itself, as it cannot produce enough energy to counter the force of gravity. When this happens, it gives out so much energy that it explodes with intense ferocity in an explosion that is known as a supernova. After the supernova, the blue giant will be crushed into a relatively small neutron star due to the strong gravity of the blue giant. However, if the neutron star has a mass more than the mass of five main sequence stars, the gravity will collapse in on itself forming one of the most feared objects in the universe a black hole.
As opposed to a blue giant, a main sequence star will simply expand into a regular red giant after its supply of hydrogen is lost and when it exhausts its supply of helium, it will merely shed off the gas and contract into a white dwarf, which is relatively bigger than a neutron star. White dwarves, neutron stars and red giants are also three of the six main types of stars. One more star would be the red dwarf, which is the most common and has a mass of about forty percent of a main sequence star.
Stars produce energy by nuclear fission. The hydrogen atoms in the star’s core have so much energy that they break apart and fuse with helium atoms in the process creating energy via nuclear fusion. After this light and heat energy is created, it flows out through the radiative zone. In the radiative zone, the energy is jostled around so much that it takes millions of years to radiate outwards. The energy waves are severely weakened by the journey that they cannot radiate out any longer, instead, they reach the photosphere through a violent process known as convection. Besides these main stars, there are many other types of stars that are in the universe; all that is left is to find and categories them all.