Sunday, April 30, 2017

Stellar evolution

                                 
                                                                  Stellar evolution



                           Stars make up almost fifty percent of our whole universe. Although they just seem like huge chunks of extraterrestrial material, they actually have a life cycle! They are not alive, but still have a cycle.

                            All stars start with huge clouds of dust particles. The force of gravity brings these particles together and forms denser clumps. In these clumps , hydrogen atoms start to fuse together and become heavier. This process is called nuclear fusion. Slowly, these small stars start to generate heat. Soon enough , they ignite and are in the main sequence of the star cycle.This is the stage that the sun is in. This is also the longest stage in the star cycle! This stage takes about 4 billion years to be completed! After this stage the star will take more energy and balloon up. This might burn a few planets to ash. this stage of the star is called the red giant. It is called the red giant because it glows red. Then the star will shed its outer layers, compressing itself. The outer layers form big clouds called the planetary nebula. Then the center of the nebula cools down and finally becomes a white dwarf. This is the route our sun will take as a star. Stars many times bigger than our sun with explode and will scatter stellar material far away. this will cause formation of new stars. This process is called a super nova.  These clouds of stellar material can form new clumps. these clumps may have protons and electrons which will be crushed into neutron stars. Another star that is 10 times bigger than the sun will shrink and form a tiny area of infinite density. this is called a singularity or black hole.

                           The cycle of stars is very ,very long. Sometimes a trillion years. These huge masses of rock that make up most of our universe are seeming like they are alive. They grow shrink and destroy other things in outer space.