Main Sequence stars make up about 90 percent of the stars in your universe. These stars are ones that are fusing hydrogen into helium at their cores. Our Sun is a Main Sequence Star. To create a Main Sequence star, an interstellar cloud goes through seven evolutionary stages which take approximately 40 to 50 million years.
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
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At that point, the star begins to fuse helium into carbon in the core. This is called helium fusion. In order for this to happen, the core’s density has to increase and the temperature has to reach about 100 million Kelvin. However, a complication arises when helium fusion begins. The star’s core is degenerated and the burning becomes unstable since the core is not able to accommodate the fusion. The increase of internal pressure and temperature caused by the burning of the helium leads to an astronomical increase in outward pressure. This is, eventually, able to regulate and the core is able to expand and decrease its …show more content…
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
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
The star has been losing fuel and is burning out, so the star will begin to collapse. When collapsing part of the star will shoot into space and scientist believe this is how a supermassive black hole forms. When the hole is forming, dust and gas is collected from the galaxy surrounding the black hole. Light cannot be released because matter is squeezed together in a small space. Stellar black holes are small but dense and can have 20 times more mass than the sun. Mass is the property of a physical body. When a black hole is forming it is possible for mass to be pulled from stars around the whole. This will help the hole grow in power and
Star formation is a rather simple process. Gasses in space clump together with dust and rock. Over millions of years these materials begin to form small orbs. Eventually it the clump will get big enough to create gravity. The core will become hot from the constant pressure and will use hydrogen to make helium using nuclear fusion. This fusions creates a tremendous amount of energy creating a fiery ball in space.
Main sequence star types include,red dwarves,yellow dwarves,blue giants,red giants,red supergiants.Stars spend most of their lives
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
For the low-mass stars, the expansion to the red giant phase will begin when about 90% of its hydrogen has been converted to helium. During the contraction of its core, a complicated sequence of events occurs. The shrinkage required to produce the energy radiated by the large giant causes the core to shrink to the dimensions of a white dwarf, while hydrogen continues to burn by nuclear fusion in a thin shell surrounding the core. This shell provides most of the energy that is radiated away by
The life cycle of the Sun starts like all stars with a cloud of dust and gas made up of mostly hydrogen. If the cloud cools, it will shrink because of the gravitational pull between the particles
Stars like our Sun, which are no more than 1.44 solar masses, will undergo fusion of hydrogen into helium. Over its life time the star slowly uses its supply of hydrogen by fusing it into helium. These reactions require high temperatures. Eventually the star will completely fuse hydrogen into helium in its core leaving inadequate amounts of thermal pressure to balance gravity. This will cause the centre of the star to contract to compensate for the heat energy lost.
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
At some point in the future when the hydrogen runs out, at that point the star will start to collapse itself under its own weight. It get denser, hotter until the point where it starts to use the helium atoms themselves as the fuel for the fusion. As the star begins to fuse helium, it creates more energy and that causes the outer layers of the star to start to expand. One day our sun will grow so large that it will swallow up the inner planets of our solar system. It will become a red giant, for the sun this will be the beginning of the end. Then they explode and become a supernova or for some biggggggggggeeeeerrr stars it would be a hypernova, which is waaaayyy stronger than a supernova; supernovas are some of the most beautiful sights in the universe. Lucky for us, our sun is too small to even explode and become a supernova. These explosion of stars are so powerful that it can outshine the whole galaxy during its explosion. For the
Orion has two of the brightest stars, be Betelgeuse and Rigel. Betelgeuse is a red supergiant. The gravity of the star squeezes its core tightly, heating it to billions of degrees. It then fuses the helium to make heavier elements. When that happens, the star no longer produces energy in the core. Without the reactions in its core to push outward, gravity quickly causes the core to collapse, forming a neutron star.
They are very bright since they have large diameters, but with low surface temperatures compared to the Sun. When the helium in the core is completely used the core collapses again.
Stage 8 is when the star starts to run out of fuel. It has spent close to 10 billion years burning hydrogen in its core and now it’s starting to run low and almost empty of the fuel it requires to keep burning. As the hydrogen starts to run low, helium levels start to increase in the higher temperature core as well as on the surface. However, the surface helium isn’t as noticeable because it doesn’t burn as high or fast as the inner core. But as the hydrogen completely runs out, the nuclear fusion subsides and a core of non-burning helium grows, forcing the burning of the star to head out of the inner core and up to the outer core. At this point, the radius of the star starts to grow rapidly because of the gas pressure and the core shrinks under the pressure of gravity.
Gravity pulls dust and gas together until it forms a ball. After a bit of time, the temperature rises from all the gas and dust bumping into each other under the great pressure of the surrounding material reaches around 15 million degrees. This is called a protostar, and it reaches a temperature of about 10 million Kelvins. This is where nuclear fusion occurs, and a star is born.
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.