Protostar Nuclear Fusion

When stars died, chemicals other than hydrogen and helium formed, which led to the next level of complexity—Heavier Chemical Element. Most stars spent about 90% of their life over billions of years on during protons and hydrogen nuclei into helium nuclei. When they run out of fuel, the furnace at the center of the star stopped supporting the star, and gravity took over. Small stars did not have much pressure at the center. They burned hydrogen slowly over billions of years at relatively low temperatures. When they died, they would slowly fade away. However, great stars had so much mass that they can create enormous pressures and temperature, and when the giant stars ran out of hydrogen, the temperature got cranked up even higher, which led the star to collapse. The high temperature that the collapse caused was able to make helium nuclei fuse into nuclei of carbon. When a star used up its helium, it collapsed again, and the cycle started over. The star heated up and began to fuse carbon to form

Stellar evolution stars exist because of gravity. The two opposing forces in a star are gravity (contracts) and thermal nuclear energy (expands). Stage 1 Birth is where gravity contracts the cloud and the temperature rises, becoming a protostar. Protostars are a hypothetical cloud of dust and atoms in space which are believed to develop into a star. Astronomers are fairly certain of their existence. Protostars are formed about a million years after a gas clump from an interstellar gas cloud has started

The life cycle of a star is dependent on its mass. The larger the mass, the quicker it will die out, whereas stars which are no more than half the size of our Sun can live up to hundreds of billion years. However no matter how large the star is, they all begin their lives in a nursery known as a molecular cloud.

A nebula contains dust and gas where gravity causes these to group together. Before the star is formed, the protostar will need to attain hydrostatic equilibrium by balancing the gravity getting atoms in and pushing heat and light out with radiation

After approximately 10 billion years after the star is considered to be a main sequence star, the hydrogen at the center of the core is depleted. This causes the nuclear fusion which had been previously fueling the star to die out. Helium replaces the hydrogen in the core, and the inner core begins to shrink due to gravity. This process speeds up once all the hydrogen is completely used up. The radius of the star has increased

Stars go through phases with each one altering the star. They start as a protostar then ignite to

One day the universe will turn dark forever as the last star fizzles out and that star will most likely be a red dwarf. When a red dwarf star forms it possesses important properties that give it the potential to host rocky planets similar to Earth. Therefore the creation and resulting properties of red dwarfs form stars that can provide energy to planets which may one day be hospitable to life forms. First the process of formation of red dwarfs will be explained. Then, the properties of these stars will be examined. Finally, the importance of red dwarf stars’ existence will be considered.

The Nebula is the first stage which the star is born. The Nebula is actually a cloud of hydrogen gas and dust in space. There are a couple different types of

First, I will discuss protostars. A protostar is a very young star that is gathering gas from a giant molecular cloud. “The protostar phase of stellar evolution lasts about 100,000 years”. (www.universetoday.com) As time goes on, pressure and gravity increase, which therefore forces tho protostar to collapse down. The energy released by the

Stars are born in a Nebulae which a clouds of dust and gas (mostly hydrogen). In the stellar nurseries the dense parts undergo gravitational collapse and compress into a rotating gas globule. The globule is cooled by emitting radio waves and infrared radiation. It is compressed by gravitational forces and also by shock waves of pressure from supernova or the hot gas released from nearby bright stars. These forces cause the roughly-spherical globule to collapse and rotate. The process of collapse takes from between 10,000 to 1,000,000 years.

You are probably wondering where did these things come from and how are they formed? Well I am about to tell you, Low mass stars are formed when all the helium has fused into carbon, then the core collapses. As the star collapses, the outer layers of the star are expelled. A planetary nebula is formed by the outer layers a massive star that will undergo a supernova explosion. Then when the low mass star is done forming after billions of years they start to become giants.

After a star lives for about 1 million years, it becomes a main sequence star. Once it becomes a main sequence star, it will then go through a proton-proton chain reaction. Since the force of gravity goes inward, the force of fusion will then go outward from the core. This process will continue for about 10 billion years even when the star is "burning" Over those ten years, the stars will eventually slowly run out of hydrogen. After it runs out of hydrogen, the core will fill up with helium.

The first process every star goes through before its end is the process of their core shrinking. When stars of at least .4 M begin to exhaust their hydrogen supply, the hydrogen starts to fuse in a shell that is outside the helium core. As the shell burns more hydrogen it is also producing more helium, this allows the core to increase in its mass and temperature. When the temperature increases greatly, helium fusion begins to start in what is called a helium flash, causing the star to rapidly decrease in its size and increase its temperature. Once the star has fused all of the helium out of its core, the product of the carbon will fuse which produces a hot core along with the outer shell made up of fusing helium. The more massive a star is,

Stage Twelve: The carbon core is no longer making any energy. Though, the outer layers are still burning hydrogen and helium at this point. Nuclear usage/burning is rapidly rising though! Outer layers are cooling down and increasing in size while the burning begins to be unstable again. The shell has series of very explosive helium-shell flashes which occurs as a result of pressure that resided in the shell. The outer layers expand/heat and cool/contract in pulses. Extreme heat and ultraviolet radiation causes the inner parts of the surrounding cloud (of the star) to become ionized. It is now a Planetary

Indecent bodies like the sun. Stars are made up of big exploding balls of gas, mostly hydrogen and helium. The sun is similarly a star made up of huge amounts of hydrogen, undergoing a continuous nuclear reaction like a hydrogen bomb. Stars come about when vast clouds of hydrogen, helium and dust contract and collapse due to gravity. The clouds came from astronomical plasma from “The Big Bang”, but the dust comes from the supernovae of other stars.