Star Life Cycle

The churning motion of the material in the convective core causes the nuclear ash of helium to be mixed with the surrounding hydrogen fuel. This motion ensures that virtually all the hydrogen will be available to the nuclear fires that heat the star.

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 Low mass stars spend there main life as a fusion machine which turns hydrogen into helium and a very slow and methodical pace. When the energy released by this fusion reaches the surface it is released into space and this is the star luminosity. Over a long, long time sometimes billions of years a low mass star consumes the hydrogen in its core and converts it to helium, at which point the core starts to contract and shrink. Once all of the hydrogen inside the stars core begins to become totally exhausted, the core pressure gives way to the crush of gravity because it has no more fusion occurring in its core at that time. As the core shrinks rapidly and the outer layers start to expand the stars shape begins to grow in size and its luminosity becomes extraordinary brighter due to the outer shell starting to produce fusion more rapidly then the core did during the main sequence life of the star. As this situation grows more rapidly and extreme the core starts to rapidly burn again and fuse its core helium into carbon. Then just before its final death the star ejects its outer layers into space. This leaves only the degenerate carbon core and since this core is still very hot it emits intensely powerful ultraviolet radiation and glows brightly in what is known as a planetary nebula. The nebula fades and cools over around a million or so years and we are left with a white dwarf cooling indefinitely till

After the core of a star has depleted all its hydrogen in fusion, it undergoes its final stages of its life, or in other words, its death. The process path of a dying star depends on its mass. Low mass stars, from about 0.4 up to 8 solar masses will evolve from a planetary nebula to a white dwarf. Stars with larger the 8 solar masses will form supernovae, than either a neutron star for intermediate stars (8-25 solar masses) or a black hole for high mass stars (greater than 25 solar masses).

The life cycle of the star is a long process that has taken place for billions of years and will continue to take place long after our star is no longer in existence. In this essay I will be explaining the magnificent process of how a star is first born till the end of its life cycle. First, I will be explaining how the star is first formed in all its beauty big or small. Then, I will be explaining the path of an average star like our own sun will take. After, I will be explaining the journey of a massive star in all its glory till its destructive end. All stars are first formed in clouds of gas called nebulae, turbulence deep within the nebulae causes cores to form as the mass begins to grow the nebulae begins to collapse upon itself due to

What is left after the huge explosion is another dwarf star, a neutron star, or the fierce black hole. A neutron star is about the size of a city like Los Angeles, but has the mass of about two suns. This means it is incredibly dense and has an unbelievable gravitational pull, almost 2 billion times that on earth. In fact, this pull is so strong that it bends radiation and allows astronomers to see the back of the star. They also spin up to 48 thousand times per minute due to the energy from the supernova.

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,

This star is formed after a large star has had a supernova explosion. These stars are usually very dense and will eventually produce a black hole. Magnetar is a neutron star with an extremely strong magnetic field. Magnetar stars are highly magnetic objects, they are even stronger than Earth. It is also 100 to 1,000 times stronger than radio pulsar. Because we are unsure how this star can be as strong as it is, theorist say it would have to rotate between 100 to 1,000 times per second. Brown Dwarfs is the in between size of a giant planet and a large star. This star is also a very dense star, but not as dense as the white dwarf. When a star is dying it squeezes all its matter into a tiny space, this is called a Black Hole. Their gravity is so strong from all the matter in a tiny space that nothing, not even light can escape. You can’t detect a Black Hole with the naked eye because it's actually invisible, you need a science telescope to identify them. The Cepheid Variable stars light brightens and dims many times. It’s like when the sun is out then goes behind a cloud then comes back out

“As the protostar radiates, it shrinks in size to generate the energy that replaces the radiated energy”. In turn, a balance is formed between cold temperatures and high densities, meaning that the star will have to generate heat proportional to the amount of dense particles within the star. Additionally, the more dense a nebula is, the faster it will form; and over time, the core heat of a protostar will will begin to approach 10 million degrees Kelvin, forming the perfect conditions for this

At this stage there is not much difference in their structure other than sheer size. Both stars are held together from the balance of gravity attempting to shrink them and heat’s attempt growing them. The heat and the star’s light come from the nuclear fusion of it’s core, causing the star to look luminous. Although luminous and small in it’s appearance, stars are actually large like the sun and extremely far away.

This is a giant star that had consumed its core .helium is accumulated in the core. The star takes on a red color after a helium burning red giant run out of helium in its core the star's core starts to collapse and heat up .They are the largest known stars .They are very similar to red giants .This star is nebulosity surrounding a star’s shell or envelope of nebulosity. This star is made of dust ,hydrogen helium and more gases . It usually can be found in between planets. Originally nebular was a name for any diffuse astronomical object. The winds from this star are also responsible for producing the spectacular filamentary. This is a giant star that had consumed its core .helium is accumulated in the core. The star takes on a red color after a helium burning red giant run out of helium in its core the star's core starts to collapse and heat up .They are the largest known stars .They are very

A nebula is a star nursery where millions of new stars are created, nebulae vary is shape, size and temperature.Within the dark parts of a nebula are where the stars are usually born, within these dense, dark areas hydrogen-gas ,clouds and dust begin to spin as gravity crushes this matter into a super dense spherical shape, the beginning of a star.

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.