Stellar Evolution Essay Examples
Stars progress through a sequence of events which is mostly influence by the force of gravity and effort of the star to retain its equilibrium. The life cycle of stars start with formation of the star (giant molecular cloud). A t this stage the star is comprised of particles and revolving masses of gases (e.g. hydrogen and helium). These particles and gases are kept at balanced by the gravitations pulls. These forces keep these elements of the star from collapsing. However, over a period of time the hydrogen gas is depleted. As a result, the cloud of particles and gases experience a shock wave (gravitational collapse) due to the loss of equilibrium. As a result, the clouds collapsed into smaller fragments known as the protostars.
The gravitation force in the protostar pulls the clouds of particles and gases together so as to regain its stability. As the protostar contract, the temperature of the protostar increases due to the conversion of the gravitational energy to the kinetic energy. As the particles move towards the centre of the photostar, they cause friction which lead to formation thermo-kinetic energy. The more the clouds of the photostar contract, the more the temperatures rise. This increase in temperature and the nuclear reaction of the particles is what causes the photostart to be luminous and hot.
On the other hand, the high temperatures cause the gases and the particles to expand outwards. This expansion creates outward pressure on the particles and gases. The outward pressure and the gravitation pull (opposing forces) is what make the star to regain its equilibrium. This stage will depend on the supply of the hydrogen in the star. Once the hydrogen level drop, the contraction continues and the mass of the star reduces. After exhaustion of hydrogen and burn out of nuclear fuel what remains is the core of the star. The core moves from white, to red and eventually to black dwarf (black hole).