Essay On Famous Stars

Thesis Statement: Supernovas are big explosions of light that occur when a star has a lot of fuel inside it which causes the star to explode.

The sun is usually a hot ball, a yellow dwarf star that glows gasses at the central part of the solar system.

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

While learning in this unit in astronomy, something that caught my attention was called "starburst galaxies." Galaxies in general are basically billions of large independent groups of stars that exist in the universe. What sets a starburst galaxy apart from a regular galaxy is the fact that starburst galaxies have an exceptionally high rate of star formation inside of it. Some of these galaxies are so active that they are forming thousands of new stars every year, compared to the Milky Way producing about one star per year. This furious formation of stars typically happens when galaxies are in the process of or have recently undergone a collision with another galaxy. The gravitational interaction between the two galaxies sends strong shockwaves through enormous clouds of gas, making them collapse and create star forming regions. These develop some of the most gigantic stars in our universe; huge blue stars with over a hundred solar masses.

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.

Stars, such as our sun begin their life in an entirely different form from the one we come to recognize. Their lives begin in the bitter cold, around 10 degrees Kelvin, which is only a few degrees above the 3 degrees Kelvin temperature of the background of space itself. Their density is also extremely sparse, with a density of around 1 billion particles per cubic metre, which is only a wisp in comparison to the density of around 1410 kilograms per cubic metre that the sun like star will have during its time on the main sequence. Although they may be quite low in density, the clouds are absolutely enormous, spanning up to tens of parsecs (an astronomical unit of measurement that is determined to be around 19 trillion miles) across. In these clouds, there is an abundance of molecular and atomic gases of various types, which will serve as the rough material that will be used to create the stars and solar systems. Hydrogen is the most abundant element found within these clouds, although they can also contain many other trace elements of metals and gasses.

As the star begins to run out of hydrogen fuel the core inside the star begins to collapse while rising in temperature, which causes the core to heat up rapidly pushing the outer layers of the star outward causing them to expand and cool the star is now a red giant. Average stars like our sun will have a relatively peaceful ending toward the end of their red giant phase. The star begins to pulsate releasing its outer layers resulting in solar winds, as these layers begin to drift away only the core remains, this is considered a white dwarf. Eventually the white dwarf will consume all its energy after this happens it will become a cold black dwarf. Massive stars come to an end much differently, after the high mass star runs out of fuel the outer layers of the star begin to collapse upon the core, and then are released in a massive explosion into the cosmos this is called a supernova. After, either a neutron star or a black hole remains these are vastly different a neutron star is an incredibly dense object made up of sub-atomic particles called

When a sun like star like the sun sheds most of it’s mass it is called a planetary nebula.

Stage 10 in the death of a star, you would start to think that with the core collapsing, that the star would just collapse and break apart. However, this only happens with starts under ¼ Sol and takes about a hundred billion years at the least. However, a star like our Sun, doesn’t die quite that quickly. Even under all the collapsing and expanding as a Red Giant, the core starts to burn helium in its core. Once this burning is about 100 million Kelvin and the density in the core has risen to the right level, the helium begins to fuse with carbon, which causes the reactor in the centre of the star to

Most stars, around 70 percent, are red dwarves, which are less massive than the sun. These stars are immortal, to our purposes. Their lives are several orders of magnitude longer than the sun's. There are many more that aren't red dwarves but are still less massive than the sun. Most stars we can see with the naked eye, however, are more massive, and stellar lifetime decreases rapidly with mass. There isn't a red dwarf close enough to be seen naked eye. So most that you see in the

It is a large bright star with a cool surface. Just like the Sun, it eventually runs out of hydrogen fuel at its center. Red Giants have a diameter of about 10 to 100 times the size of the Sun. The reason for why the Red Giants are so bright is because of its size, although there surface temperature is less hot than the Sun’s. If you were to measure the temperature, it would be about 2000 to 3000oC. Red Giants, very large stars, are also often called SuperGiants. These stars sometimes have diameter of up to 1000 times the size of the Sun, also having more than 1 000 000 times the luminosities of the Sun (Life cycle). These stars live for only a few thousand years to 1 billion years. Eventually the helium in the core runs out and fusion stops. The star shrinks until a new helium shell reaches the

“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

In most cases a star will move into the planetary nebula phase, as an expanding, glowing shell of hot gas also known as plasma. This happens from a low-mass star in the end of their red giant phase, becoming unstable. The exterior layer drifts away from it’s core, which is now consider a white dwarf star, due to stellar winds. If the dying star have a mass of over 8 suns, it will become a supernova. Just like a planetary nebula, the cause of it is when a star runs out of nuclear fuel. From the massive star’s lack of outward pressure to balance its inward gravity, the star collapses into the core expelling a nuclear explosion. Also like the nebula, gas and dusts are scattered around space that will be used for the birth of future stars. At this point, the former supergiant is either a neutron star or a black

Stars a balls of gas that are luminous meaning that they give off light. Star first start transition begins from clouds, a cold molecule of hydrogen that gravitationally collapse creating fragments into many pieces that slowly form in to individual stars. Stars are then held by their own gravity and is made of 75% hydrogen and 25% helium two of the elements in the periodic table. Hydrogen has the symbol of H and is the lightest and also simplest element in the periodic. Helium had the symbol He and had the lowest boiling point compared to the other elements in the periodic table. As time eclipse stars converts elements of hydrogen to helium that is why the ratio of the sum is 70% hydrogen and 29% helium.

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.