Birth of a star
The universe is a wondrous place where many processes, that defy all imagination,occur. One of these magical phenomena is the birth of a star. Born out of nebilas, a star is the end result of high energy; nuclear fusion.
Nebulas are huge interstellar gas and dust clouds, whose size can be many light years across. They are the birthplace of stars, containing enough cosmic dust to produce thousands of stars, like our Sun. Stars are primarily made up of two molecules, hydrogen and helium. Nebulas also contain larger, more complex molecules that are the reminants of old stars. These stars violently explode creating what’s called a Supernova.
The importance of the gravity
Due to irregularities in the density of the interstellar gas clouds gravity at the height of these regions will play a free role. The gas molecules present are drawn closer to each other, causing them to lose their potential energy. This loss of energy results in an increase of the temperature.
As more and more gas molecules are drawn towards each other, the temperature will continue to rise. The huge gas cloud will eventually be broken down into smaller nebulae, each giving rise to the formation of a star.
The particles are in the center of the gas clouds being pulled towards each other more than in the outer regions. This ensures that the entire cloud starts to rotate at an exponential rate. When the temperature reached in the core of the nebula 1727 ° C, the hydrogen molecules are split into hydrogen atoms. Finally, a rotating mass of gas with a huge temperature obtained, which constantly collapsing core. This early stage in the birth of a star is also known as a proton-ester. The further evolution of the ester is dependent upon the mass of the proton ester. Will protostars with mass can thus smaller than those of the Sun never reach the temperatures of fusion. These stars are called brown dwarfs. The temperature in the core will, however, if their mass is large enough, eventually increase to 10 million degrees Celsius. At this temperature, there occurs a nuclear fusion of hydrogen into helium and deuterium. This nuclear fusion reactions transmit energy which creates a gravitational pressure to the action of the force of gravity on the star counteracts. From As a result, there will be an equilibrium between the gravitionel pressure and gravity, in which the star is fully balanced. When the star has entered this state of balance, they will be mass depending evolve. Will be small stars that hydrogen is gradually merge as much slower to evolve than massive stars.
How long the star will stay alive?
The lifetime of an ester depends on the amount of gas that are present in the core. When these gas supply runs out, there is no fuel for the various nuclear fusions more. Consequently, there will be an end to the balance between the gravitational pressure and gravity, and the star will collapse.