The GAR period is a period in which a star has contracted large clouds of hydrogen, helium, and dust before the last sequence. This is known as a Protostar.
A protostar takes about 100,000 years to reach the main sequence. This may seem like a long time to us, but for a star it isn’t! Any thing that disturbs the Protostar may upset its Equilibrium (Chemical Reaction) which may cause problems in the star. One of these disturbances includes shockwaves from the supernova.
A physicist Sir James Jeans made a formula to show (under appropriate conditions) to show when the gravitational contraction of the protostar would begin. This formula is known as Jean mass.
The Protostar's Fragmentation
Stars are often found in groups of combined clusters which seem to have formed about at the same time. Turbulent velocities compress n shocks, this makes clumpy structures within the within the giant molecular cloud. This is referred to turbulent fragmentation. Then, the cloud breaks up to smaller area which beaker into smaller areas and because of this process, a cluster of protostars are born.
How a Protostar is Heated
As the cloud contracts, it increases in temperature. This is not caused by nuclear reactions but by gravitational energy. As a particle, it decreases its distance from the center, therefore, this will result in a decrease in gravitational energy.
Where Protostar is located in the Life Cycle of a Star
A protostar is the birth of a star. They are stars that are starting out in their life as a star. They don’t get very warm, and are pretty cool for a star’s temperature.
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