Tatooine’s close encounters with a death star

During the nighttime, millions of uncountable tiny glowing objects are seen floating in the sky. The small glowing objects in the sky are fossil-fueled balls of gas that are formed through the collapse of clouds that contain cold gas in the sky. The gas is compressed, which make it heat up and then it forms a plasma. On earth, they are the most common astronomical objects which represent the different galaxies that exist. Stars are mainly the reason why skies at night are filled with glowing objects. They are the reason why the skies, just like earth, have elements such as oxygen, carbon dioxide, nitrogen, and the features of the stars are also similar to those that make the planetary systems full or complete. Their temperature is also determined by the by the mass of that star. The photons which are packages of light that are produced by stars are formed when the temperature gets to a range of 4 million degrees Celsius. The high temperature then causes nuclear fusion to helium and causes the light. The following paper seeks to discuss stars in general, how they are formed, how they die among other aspects.

How they are formed

Stars are filled in the galaxies, and they are mainly formed by the dust that exists in the galaxies. When chaotic changes occur in the galaxies, the clouds go through vicious and dominant forces which rises the protuberances, and the mixture of the gas and dust creates its gravitational force that enables the collapse of the gas and dust (Schwarzschild, 29). During the process, the protostar, the material at the center of the star, can gain so much heat and in time can form a star. Multiple stars are however formed in the situation where the collapse of the cloud and dust can break.  An example of when the stars break and form multiple stars is such as the Milky Way which is a galaxy that contains stars, clouds, dust and multiple stars that are formed using the process fore stated.

During the process of forming the stars, the heat at the center of the star starts collecting dust and clouds which enables it to continue building up the star. However, not all the stars and dust are used up during the process. It is then, during the formation of the stars that some dust and clouds also form other planets, stars comets or asteroids (Abbott et al. 131). If they are not able to make any move, the cloud and dust remain the same. In other cases, the process of the collapsing may also happen not as expected. The collapsing can either be faster or slower. An astronomer, James, McNeil, was able to study an interstellar cloud of dust that seemed to blow brighter than the other stars. After close examination, Neil together with the observer team of Chandra X-ray of NASA the explanation was determined, and the explanation was that the nebula was close to the Nebula Messier 78 and its interaction with the young magnetic field was interacting and the gas which in the end led to increased light in brightness.

The stars that are bigger compared to 8% of the sun the process of fusion that happens in their cores makes it possible for them to produce heat and light (Huang et al). The production of these elements enables the star to live longer and prevent it from explosion through the flow of energy from its core to its outer shell. A star at such a stage is known to be at its “Main sequence” stage and is the stage at which stars spend most of their lives depending on the nature of the star.

Main sequence stage of stars

When the star reaches the size of the sun as we know it, duration of fifty million years is required for the star to go through the process its collapse to its maturity into adulthood. In an example of the sun, it is expected to stay in its current matured state for a duration of around ten billion years. Stars are powered in the process when it fuses with hydrogen and forms helium from the core. The energy that is produced from the core of the sun flows from the core to the outer layer, and that gives it more time to live and reduces the chances of exploding and keeps the star in shape. The outflow of the energy keeps the star from crumpling to its gravity and the energy flowing to the core make it shine.

The moment a star is in its main sequence stage, it is bound to extend to different types of luminosities and colors which are categorized into the characteristics it produces. The stars are then measured depending on their proportion of their size and luminosity of the sun in our solar system. The stars that are categorized as “Dwarfs” are the stars that are less bright compared to the sun. The other stars that are brighter compared to the sun are referred to as “giants.”

In a more detailed explanation, “red dwarfs” are the stars that only have 10% of the size of the sun and can only emit only 0.01% of the energy in its emission. It also glows in a way that it shows no strength compared to the sun with a temperature that ranges from 3000k to 4000k (Sutherland and Daniel, 6). However, due to their lack of vigorous use of much of their energy, they are known to be the most in the sky and also live the longest in their galaxies with lifespans that extend to tens of billions of years. Stars that do not have enough mass to maintain the fusion are known as “brown dwarf,” and the temperature of their cores are not high enough to start and sustain hydrogen fusion

The most massive stars that are known to be a hundred or more times more than the sun are known as “hypergiants.” They are also known to have a surface that has a temperature that has ranges of around 30,000K (Sutherland and Daniel, 6). They are also known to produce more than thousands in the times of more than the sun although it drains more of their energy faster, and they only get to go for a lifespan of a few million years. Many of the hypergiants existed in the early universe, and to this day only a few of them exist in the Milky Way galaxy.

Death of the star

However, regarding the life of a star, it’s only proportional in a way that the larger the star, the shorter the life of the star. Most big stars have a range of five billion years to live. However, most of them get lucky in a way that if any of the stars are fuse its reaction in the core with Hydrogen, then the reaction stops. Once the star can gain access to the energy of reaction it produces, the core of the star becomes even much hotter, and the hydrogen that surrounds the star continues reacting with enables it to create a shell that surrounds the core. The force becomes intense with the core having a lot of heat pushing out and the hydrogen creating a shell that covers the core. The core still becoming intensively hot, continues pushing out and the hydrogen also does its part of creating the shell that contains the core inside of the star. The process gets to a point where the star becomes a red-hot giant because of the activity in the star of pushing in of hydrogen and pushing out of the core in the star.

The core of the star’s energy is strong enough regarding size, the collapsing core that contains clouds and dust becomes capable of handling even more components that introduce new and stronger reactions that consume the helium and discharges different types of elements. These reactions help the star get more life by introducing an extended life but, the star is still bound for ‘death.’ The star continues with the reaction which makes it even more unstable as time goes by burning furious and in some cases up to the point of its death. The reactions become more vigorous, and the star explodes, where the outer shell is thrown out and disappears into a covering that prevents the corrosion of dust and gas. The steps that follow after that vary with the size of the star.

Types of Stars

White dwarfs (the average stars)

For such stars, those that are similar to the sun, they continue to react with their outer layers until their inner core is exposed and thus they become white dwarfs. At the star is dead and still hot burning coal is called a White dwarf (Otoniel, Edson, et al). For White dwarfs that are the size of earth and contain the size of a star have been known to be known to raise the question of how they did not collapse further and how they were able to sustain the core of their mass.

The explanation provided to answer the questions raised indicated that the pressure produced by the fast-moving electrons are the things that keep the star from exploding or collapsing. Such white dwarf stars can develop denser cores that make them able to sustain the energy. In white dwarfs, when the diameter of the star is small, the density of the star becomes higher which makes it even bigger in mass compared to other stars which are bigger in mass. These types of stars are also common, and the sun is also expected to also become a white dwarf before it cools down into oblivion but in billions of years from now.

Many of the stars that turn into white dwarfs are those star that are about 1.4 times the size that of the sun. Masses that exceed 1.4 times more than the sun have electron pressure that is not able to support the core towards further collapse; they suffer different fates.

White dwarfs become Novae.

White dwarfs experience demise as a nova in a multiple star system. The novae were before thought to be new stars but were later understood to be old stars and in particular, white dwarfs. The gravity of white dwarfs, when accompanied by other companion stars, is also known to drag matter and in most cases hydrogen, from the shell of the companion star to its system. The white dwarfs accumulate as much nitrogen as required until it is enough for its fusion.

Once the white dwarf’s surface has accumulated enough nitrogen, the fusion begins, and white dwarfs brighten significantly where the remaining material of the white dwarf is ‘expatriated.’ The fusion then continues for a couple of days and then later cools down, and the white dwarf starts going through the same process again when it comes across more nitrogen. In other instance, massive dwarfs especially those that are close to the 1.4 solar limit, pull so much matter by its gravitational matter until they collapse and explode entirely and become a ‘supernova.’

Supernova

In every half a century, supernova explosions happen in our galaxy and are considered to be the most violent events in the universe that they produce flashes of radiation. They have been categorized by the properties that are observed optically. Several types have been observed in the process, among them being Type II supernovas and Type La (Huang, Xiaosheng, et al). Type II supernovas have shown evidence of hydrogen in the remaining ruins of the white dwarf. Type La supernovas, on the other hand, have not shown the evidence such as type II supernovas. The research conducted has improvised in the categorization of the supernovas. Type Ia supernova is when the thermonuclear explosion breaks down a white dwarf star. Type II, Type Ib and Type Ic explosion are mainly produced when a during the collapse of a massive star, particularly those that are almost the highest limit of the white dwarf of 1.4 the mass of the sun.

Type II mainly occurs in regions of the galaxy that have more bright and young stars which are massive. Most of them are like ten times more than the sun but do not occur in elliptical galaxies, those which are commonly occupied with old, low mass stars (Abbott et al). Type I and Type II have shown quite similar features. However, Type Ib and Type Ic differ because of their prior loss of the hydrogen to the explosion.

(a)    Core-collapse supernovas

When the core of a star gets exhausted, it collapses and in less than a second, and a neutron star is formed, and if the star was a massive star, then a black hole is formed. After the neutron star is released, a formation of neutrons and heat is released in a significant amount and reverses the impulsion. Everything else apart from the central neutron star is blown away, and a thermonuclear shockwave goes through the stellar ruins and fuses the elements producing an intense light similar to several billion suns.

(b)    Thermonuclear supernovas

They are produced by all stars in kinds of galaxies and are Type Ia. When a dwarf star exceeds its limit of 1.4 solar masses, its temperatures rise, and it generates a nuclear fusion explosion that discharges a lot of energy, and in ten seconds the no remnants are left.

(c)    Pair-instability supernovas

Pair-instability supernovas are considered to be the most energetic thermonuclear explosion in the universe. Pair-instability supernovas mainly occur with stars that have masses that range between 140 and 260 suns (Huang, Xiaosheng, et al). Since the temperature rises to seven billion degrees at the center of the star, the instability between the outward pressure and the gravitational pull of the star could disturb the symmetry and therefore cause a thermonuclear explosion that would produce a radioactive nickel. The vibration between the gravity and the pressure would be overcome by the gravitational pull that the star would collapse and form a black hole even when an explosion does not take place. The radiation that is produced by the supernova takes about several months to several years before it disappears.

Neutron Stars

Neuron stars are formed when the stellar core at the center of a supernova is 1.4 and three solar masses (Huang, Xiaosheng, et al). The collapse of the supernova continues until the electrons and protons of the supernova combine to form neutrons and later produced the neutron stars. The neutron stars have the density that is similar to that of an atomic nucleus. Because of its density, the gravity in the neutron star’s surface is so enormous that neutron star also has the capabilities of using its gravitational pull, just like the white dwarf, to accrete gas by stripping off the nearby companions.

The neutron star also has a magnetic field that accelerates particles around its magnetic poles and ends up producing powerful beams of radiation that collects other elements around as the star rotates in the universe. When the neutron stars are rotating rapidly like how they always are, the magnetic field around them combines with the rapid rotation of the star and creates a generator that can produce an electrical potential difference of quadrillion of volts. Such kind of voltage is great enough to create a dangerous blizzard containing high energy particles.

Black Holes

In situations where the collapsed stellar core is bigger than three solar masses, it collapses and forms a black hole. A black hole is a dense infinitive object that has an immense gravitational pull that nothing, not even light, can escape from its immediate proximity, they can only be detected indirectly because of the photons that are the only instruments that humans are capable of detecting. The reason why indirect methods are the possible and reliable ways for humans to detect the black holes is that the gravity of the black holes are so immense that anything nearby material or anything on the companion star is always dragged in the black hole. The black hole formulates a disk that is on enormous temperatures and is capable of emitting qualities of X-rays and Gamma rays that show the occurrence of the underlying hidden companion.

From the remains, new stars arise

The dust and scattered pieces of the remains from the different types of supernova and novae, combine with the surrounding compounds such as gas. The heavy floating elements from the remains mix with the chemical compounds from the death of the other stars such as white dwarf. The materials are later reprocessed and recycled which builds a new platform for stars to redevelop together with other planetary systems.

Works Cited

Abbott, B. P., et al. "GW150914: Implications for the stochastic gravitational-wave background from binary black holes." Physical review letters 116.13 (2016): 131102.

Huang, Xiaosheng, et al. "Determination of RV and Distance for SN 2012cu, the Type Ia Supernova with Highest Extinction." American Astronomical Society Meeting Abstracts. Vol. 227. 2016.

Otoniel, Edson, et al. "White Dwarf Pulsars and Very Massive Compact Ultra Magnetized White Dwarfs." International Journal of Modern Physics: Conference Series. Vol. 45. World Scientific Publishing Company, 2017.

Schwarzschild, Martin. Structure and evolution of stars. Princeton University Press, 2015.

Sutherland, Adam P., and Daniel C. Fabrycky. "On the fate of unstable circumbinary planets: Tatooine’s close encounters with a death star." The Astrophysical Journal 818.1 (2016): 6.