The Creation Of A Wolf-Rayet Star

After a time, the hydrogen runs out almost completely, and it collapses. New reactions begin to take place in the core and these reactions cause the star to expand rapidly. As the stars begin to deplete their new fuel, they switch to others. New elements are formed in the cores of stars but they become too heavy. The star has reached its end growth. When it reaches the end, a tremendous amount of energy is released and it begins to shed its outer layers, the gravity is too weak hold onto them anymore. Once the layers are removed, in the stars place is a fiery core called a planetary nebula. Eventually, the core runs out of fuel and it collapses. This star is now in a very dense state, and is called a white dwarf. Eventually, the white dwarf cools until it no longer shines. This dead star is called a brown dwarf.More massive stars, however, have more violent ways of dying. Some stars turn it into a supergiant. Supergiant stars are extremely bright, and are extremely large. Supergiant stars cores, can collapse violently and suddenly. This collapse causes a tremendous explosion, called a

The main idea for paragraphs 6-8 in When Stars Explode is how stars do explode. Here are some details: according to the text,“But these nuclear reactions do not make as much energy as hydrogen did. Within a few million years, the star has nothing left." The text also said “So the star's center collapses, scrunching itself into a small, dense object. Meanwhile, the star's outer layer shoots into space at millions of miles per hour. The star has exploded!"

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

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.

The larger a star, the shorter their lifespan is, and they explode as supernovae, blasting out powerful shockwaves that create a chain-reaction that spews throughout the galaxy. Within just a few million years, the galaxy is forming stars up to hundreds of times more than a normal galaxy would. When all of the gas available is used up in about ten million years, the galaxy calms down and the period

Type II supernovaes, which are more common, occurs when a star runs out of nuclear fuel and collapses under its own gravity. In a Type II supernovae, once the star’s core surpasses a certain mass (The Chandrasekhar limit) the star begins to impolode. The core then heats up and becomes denser. Eventually the implosion bounces back off the core, expelling the stellar material into space. What’s left is a neutron star.

Wolf-Rayet Stars – These massive stars are evolved and have completely lost their outer hydrogen, so they are fusing helium and heavy elements in their core.

seen day and night in the sky. It is now known as the crab nebula, and is a breeding ground for smaller stars. Another way for a supernova to be created, is when a white dwarf siphons off hydrogen from another star to the point where it will become unstable and explode.

The deaths of normal stars give birth to neutron stars. Neutron Stars are products of the so called supernova. Supernovae transpire during the death of a highly developed star which occurs when there is not enough nuclear fuel to keep the pressure intact inside the core of a star (Gursky 1975). The aftermath of a supernova is crucial because it frees iron, carbon, copper, and oxygen along with other elements found in a star. This explosion completely demolishes the star and has the ability to transform into either a black hole or neutron star (Freddy 2006). These supernovae are extremely bright and every 200 years there is an explosion that happens to be big enough and bright enough to be seen from earth. Neutron stars are very significant within the universe. It is said that the neutron star was discovered before the before the neutron. It was Lev Landau who first wrote about and studied dense stars. He focused his research on the idea there were objects in the universe that were denser than but as small as white dwarfs and regular stars (Haensel 2007). This focus leads to the discovery of the fascinating and complicated neutron star. The end is only the beginning for neutron stars.

The burning process continues in the outer layers of the star, and they continue to expand. They can reach a maximum radius of approximately 300 times our Sun’s! The burning in the outer layers becomes unstable and they go through a series of explosive helium-shell flashes which are brought on by the pressure in the shell and the sensitivity to changes in temperature. This process causes the outer layers to pulse as they heat and expand, and then cool and contract. The core contracts and heats up as the last of its fuel is used. It becomes so hot that it expels ultraviolet radiation into the inner parts of the surrounding cloud, ionizing it. This process is called a planetary

it runs out of energy. Once the star dies, it may become a white dwarf, a neutron star, or a black

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

During the condensing of the star’s core, the neutrinos are able to escape, but the neutrons are squished together so much that their density is the same of an atomic nucleus’ density. A violent explosion happens during this process and its called a “supernova”. To put this into perspective, imagine taking something the size of our sun, if not bigger, and compacting it into an area the size of a city. This is so dense that just a teaspoon of it would weigh about 1 billion tons! Crazy, right?

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.

Main sequence stars like our own sun enduring in a state of nuclear fusion during which they will produce energy for billions of years by replacing hydrogen to helium. Stars change over billions of years. When their main sequence phase ends they pass through other states of existence according to their size and other characteristics. The larger a star's mass, the shorter its lifespan is. As stars move toward the end of their lives, much of their hydrogen will be converted to helium. Helium sinks to the star's core and raises the star's temperature—causing its outer shell to expand. These large, puffy stars are known as Red Giants. The red giant phase is actually a prelude to a star shedding its outer layers and becoming a small, dense body called a White Dwarf. White dwarfs cool down for billions and billions of years, until they finally go dark and produce no energy at all. Once this happens, scientists have yet to observe, such stars become known as Black Dwarfs. A few stars avoid this evolutionary path and instead go out with a bang, exploding as Supernovae. These violent explosions leave behind a small core that will then turn into something called a Neutron Star or even, if the remainder is large enough, it is then turned into something called a Black Hole.