Star Life

Stars All stars are born of nebulas, massive clouds comprised mainly of hydrogen, with about three percent helium gas too. Due to gravity, the atoms of the various elements in the nebula will group, bond, or "clump" together. As gravity continues to impact the behavior of the gases and elements in the nebula, a protostar is born. The process of atomic accumulation in the center of the nebula forming a protostar is known as accretion. During the accretion stage, the protostar is highly unstable.

As the protostar stabilizes and achieves equilibrium, it is in a better position to become a fully-fledged star. Otherwise, the protostar will dissipate and die. Equilibrium is achieved when there is a balance between the pressure of atoms to move away from the gravitational center and the pressure to conform to the gravitational pull at the center. Gravity is a primary and formative force throughout the entire life cycle of a star, and determines the impact it will have on the universe.

Thus, the first stage in the formation of a star is its protostar stage. Next, the protostar becomes a fully-formed object still comprised mainly of hydrogen and helium. These massive balls of gas use their own energy, fusing hydrogen and helium. These gases may be transformed into carbon, the basis of all life. In fact, when stars grow larger, they can fuse elements from carbon and thus with seeming magic create elements heavier than hydrogen and helium. This is thermonuclear fusion.

The larger the star, the more energy it has to burn, just as with people. The main sequence stage of the star's life cycle entails the bulk of the star's existence. This is the stage that human beings come to know stars: as shining balls of light-emitting gas masses. They radiate their energy throughout space, just as the sun does. The star can remain in the main sequence for billions of years. Slowly over the course of its life, the star contracts because it loses energy.

Yet while the star is contracting, it is actually gaining heat, density, and pressure. The star's core temperature rises as it contracts, because gravity is pulling energy inside the core even while there is a simultaneous pressure to emit energy out -- in the constant process of equilibrium maintenance. Large stars can burn out faster than small stars because they burn energy at a higher rate.

This is why many small stars will have a longer life span than a larger star: they do not consume their fuel as fast and thus remain alive longer. When the star stars to burn up its helium reserves, the star is on its last years of its life. This is because it requires more energy to fuse helium than it does hydrogen, thus expending the star's energy rapidly. When the star starts burning helium, its temperature and intensity can be stronger than ever before during its life cycle.

This stage of the star's life is referred to as the red giant stage. Red giants are bright but are becoming less stable than they were before. Their volatility is due to their burning of carbon. The death of stars is difficult to document and measure. A Hertzsprung-Russel (HR) Diagram represents stars visually as dots, plotted on a graph using two axes: absolute magnitude (which is basically luminosity,.