NEBULA

                                           

                                        NEBULA

        

                                                 If we translate the Latin word ‘nebula’, it would simply mean ‘cloud’.A nebula is an interstellar cloud of dust,ionized gasses.The main gases are hydrogen and helium gas, and plasma.It is form when portion of interstellar medium collapse due to gravitational force(attraction) by the particle in that medium.Many of  you think that outer space is vacuum but it aint true it is fill with medium called ether which may contain many gasses and other dust particles,and this all known as ISM(interstellar medium

                        There are many nebula till found and some of most prominent are Eagle Nebula,Horse head Nebula,Red Rectangle Nebula,Crab Nebula and many more.

                        As the material collapses under its own weight, massive stars may form in the center, and their ultraviolet radiation ionizes the surrounding gas, making it visible at optical wavelengths.The more masses clump together, the greater their gravitational attraction will be to other bodies and particles in their vicinity. As the particles clump further to form larger and more massive structures, they attract more dust and gas. The pressure inside then gets so high that nuclear fusion ensues. This results in the emission of high-energy electromagnetic radiation, which in turn ionizes the outer layers of gas.Ionized gas is plasma, and so plasma and electromagnetic radiation are now added to the mix. This now becomes the earliest stages of star formation.
                                   Some nebulae are formed as the result of supernova explosions, the death throes of massive, short-lived stars. The materials thrown off from the supernova explosion are ionized by the energy and the compact object that it can produce,other nebulae may form as planetary nebulae. This is the final stage of a low-mass star's life, like Earth's Sun.

                                                                           (HELIX NEBULA)

                                                  Planetary Nebula.

                               Planetary nebulae form from the gaseous shells that are ejected from low-mass asymptotic giant branch stars when they transform into white dwarfs.Nebula is just not the starting point of the formation of heavy masses,ironically it may be end point.Stars that evolve into red giants can lose their outer layers during pulsations in their outer layers, known as their atmospheres releasing hydrogen and helium into 9.7:0.3 ratio.It is this released matter that forms what is known as a planetary nebula.

       

                                                                     (CAT EYE NEBULA)