Stars and Nuclear Fusion Essay

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

Stars are the most recognized astronomical object in space and they represent the building blocks of galaxies. Stars distribute elements such as: carbon, nitrogen, and oxygen. A star develops from a cloud of hydrogen and helium, the dust clouds that are scattered throughout galaxies. An example of a dust cloud is the Orion Nebula. The gas and dust begin to collapse from its own gravitational pull. As the cloud collapses, the middle gets hotter. This is known as a prostar. A dense and hot core forms which begins to collect dust and gas. All this material may not end up as a part of the star but can become planets, asteroids, comets, or remain dust. A star about the size of our sun can up to 50 million years to mature. The smallest stars are

Both high- and low-mass stars respond to the depletion of hydrogen fuel in a similar manner. In order to supply the heat to oppose its own self-gravity, the star 's core again responds by shrinking. In a sort of reflex reaction, the outer regions of the star expand, causing a great increase of its radiating surface area. Although the total energy output of the star increases during this phase, the greatly enhanced surface area results in a cooling of the surface and the star takes on a redder appearance. The size and color change lead to the name of red giant for these stars. If the star is very massive, it may become what is called a red supergiant.

As this slow contraction continues, the core temperature, density, and pressure of the star continues to increase. As the star shrinks it becomes so dense that it starts to compress helium. This results in the star to swell due to the hot core and leaving a relatively cool surface. Eventually the outer layers of the star expand outwards, increasing the size of the star. As the layers continue to expand, the surface temperature continues to cool, forming a relatively large star called a red giant.

Comparing red giants to the sun, they are about 1000 times larger. Compared to the sun’s temperature, a red giants temperature is about half as much. This is because the same amount of energy has to be spread out across a much more massive star causing it to be cooler than it was before. The name red giant was given to these stars because the change in temperature causes the star to shine in the redder part of the spectrum. Stars can spend anywhere between 1000 years and one billion years in the red giant phase. After a certain amount of time, the helium finally runs out and fusion stops. Since there is no more helium, gravity pushes the star inward. The stars outer atmosphere is then blown out into huge clouds of gas and dust which is known as planetary nebulae. These clouds of gas and dust are then made to make new stars. As for the core of the star, it is still there. The star is now a white dwarf. White dwarf stars occur when the red giant loses its outer atmosphere. White dwarf stars are extremely hot because they are composed of only the core of the star which is the hottest

The first time I went star gazing I was five. My dad had driven me twenty minutes to the west of our house which landed us a couple of miles into the Everglades. Away from all the metropolitan lights of my town and others near by, I was able to see hundred of stars. I was mesmerized by their brightness and the twinkiling effect they had. A couple of days later my dad came home with the book the “Magic Treehouse reaserch guide: Space”. It was a sequel to the “Magic Treehouse #8: Midnight on the moon”, which I had read so many times it was starting to tear at the spine. From an early age I had become obssessed with the question, what lies beyond our world?

The life cycle of star is on an eternal cycle of birth, death and regeneration where the gases that form stars are ejected by the very stars when they die. This all starts with the helium gas and fusion of hydrogen. The life cycle of a star is formed from stellar nebula to high mass stars and low mass stars. Hertzsprung and Russell classified stars on the main sequence of the H-R diagram about 1910 that shows the relationship between luminosities and spectral types.

You know, because you've been told, that the Earth revolves around the Sun. You also probably know that planets other than our own have moons, and the way to test to see whether or not something is true is by experimenting. Thousands of years ago, these things were not widely known. The heavens above were anyone's guess, and the way things were was just the way the gods had made them. It was felt there was no need to truly understand them or put them in any kind of order. Astronomy is the oldest of the natural sciences, dating back to thousands of years ago. This paper is about the history of astronomy from the 1st telescope to the last astronaut. Some of the most intelligent astronomers have been discovering more and more since before the time of 500 B.C. Some of

Stars generate energy via nuclear fusion of elements. Stars of the magnitude great enough to become type II supernovae possess the mass needed to fuse elements that have an atomic mass greater than hydrogen and helium. The energy generated by these fusion reactions is large enough that it is able to counter the force of gravity and prevent the star from collapsing, maintaining stellar equilibrium. The helium produced in the core builds

A star and its planets form out of a collapsing cloud of dust and gas within a larger cloud called a nebula. As gravity pulls material in the collapsing cloud closer together, the centre of the cloud gets more and more compressed and, in turn, gets hotter. This dense, hot core is the beginning of a new star.

The temperature of the star has to be very high in order for the star to begin the process of nucleosynthesis, the process where the nuclei of lighter elements fuse together to form different nuclei, releasing energy in the process. A star can have a lifespan of millions, billions, or even trillions of years, depending on the mass of the star. Stars with a low to average mass, like our Sun, will burn longer than stars with a very large mass, because the process of nucleosynthesis will speed up for stars with a larger mass, causing their lifespan to be shorter than that of a star with a lower mass. The process of nucleosynthesis takes hydrogen and burns it into heavier elements, such as helium, allowing new elements form. A star will remain a main sequence star most of its life, burning all of the hydrogen into helium, and burning the helium into heavier

Stars are born in a very complicated way. First the gravitational collapse of a cool, dense molecular cloud sends fragments into space. The fragments then contract and form stellar cores. The stellar cores then rotate and condense as they increase in temperature, to the point that a nuclear reaction occurs. The new born star burns hydrogen into helium for 90 percent of its life and is a sequence star. A star’s mass changes as it burns more hydrogen.Once there is no more hydrogen for the star to burn off of, energy generation will stop and the core will start contracting. As the internal temperature increases a shell of hydrogen gets ignited. The star begins to expand enormously and increases in luminosity. The star expands so large that if our star started to expand like this it would swallow Mercury and

All stars are born in nebulae. Nebulae are huge cold clouds of gas and dust. The formation of protostars requires huge clouds of gas and dust collapsing under gravitational forces. The stage of a protostar last an approximate of 50 million years. As stars grow, they also expand. When the core runs out of hydrogen and helium, the contacts and outer layers of the core expand, become cold, and the brightness decreases. This is also known as a Red Giant or a Red Supergiant which mainly consists of the star’s mass. After a while of beginning the process of its death it goes through other stages.

A star's life cycle is determined by its mass. The larger its mass, the shorter its life cycle. A star's mass is determined by the amount of matter that is available in its nebula, the giant cloud of gas and dust from which it was born. As the interstellar mass condenses and loses gravitational potential energy, the temperature rises and the material gains thermal energy which is known as protostar. It is now a main sequence star and will remain in this stage, shining for millions to billions of years to come. As in sequence star glows, hydrogen in a star’s core is converted into helium, the core begins to contract and heat up. The rapid release energy upsets the pressure-gravity force balance and causes the star to expand, cool down and enter

‘There are more stars than all of the grains of sand on earth.’(Star Facts, 2005:1)