A stars final state depends greatly on its mass and a star’s mass is determined at the beginning of its stellar lifecycle. Typically, black holes, neutron stars and type II supernovas only occur in the life cycle of high-mass stars while white dwarfs, planetary nebulae and type IA supernovas occur in the life cycle of low-mass stars. To determine how each of these remnants of stellar evolution are created all that is required is to follow the stellar life cycle of both low and high-mass stars. Beginning with a star’s birth, a star could either be low or high in mass. A star is born from a giant cloud of dust known as a nebula. The mass of the star is determined by the amount of matter present in the nebula. High-mass stars will have more matter present in the nebula for them to accrete in comparison to low-mass stars who have less mater in their nebula. Interestingly, while both stars may be of substantially different masses they share majority of the same stellar lifecycle phases. To elaborate, both low and high-mass stars become a protostar after gravity gradually forces the hydrogen gas that is available in their nebula together and begins to spin. (NASA, 2013). This spinning eventually causes the temperature of the protostars to reach 10 million K (or 15,000,000 degrees Celsius) whereby the protostar becomes hot enough for hydrogen fusion to operate efficiently. Both low and high-mass protostars then become main-sequence stars as the hydrogen fusion holds their gravitational contractions in stasis and they become stable. In this state, they glow and burn hydrogen in their core, converting it into helium through nuclear fusion. The stages of a stars stellar lifecycle that follow after the main sequence star phase depend predo... ... middle of paper ... ...om collapsing from neutron degeneracy pressure it will become a neutron star. These are detectable ____ If the mass of the leftover core of a high-mass star is greater than about 3 solar masses, the neutron degeneracy pressure can’t stop gravitational collapse and there is no known physical force capable of stopping this collapse. The core consequently collapses into a black hole. As you can now see, the remnants of stellar evaluation are determined predominantly by the mass of a star right from the beginning of its stellar lifecycle. Type IA supernovas, white dwarfs and planetary nebulae are stellar remnants of low-mass stars while Type II supernovas, neutron stars and black holes are the stellar remnants of high-mass stars. Given that also each of these stellar remnants are characteristically diverse, the way astronomers detect them is equivalently diverse.
When itBetelgeuse cannot fuse anymore anything over iron, the star will not have enough energy to make heat. Eventually, the core will collapse. When Betelgeuse collapses, it is so strong and powerful that it causes the outer layers to rebound. With the rebound it will have an explosion, which is called a Supernova (Type two). The explosion has so much energy and power that the temperature becomes really hot. The temperature is so hot that it can use the fusion process much heavier than iron. The elements that were given off from the explosion are sent throughout space and are now new nebula. When the Supernova is done, it has left behind a star called a Neutron star. They form when atoms of the core of a dead star are crushed together and the end result produces neutrons. The neutrons are with electrons that are degenerate on the surface. Many Neutron stars have magnetic fields and they give off strong waves of radiation from their poles. These types of Neutron Stars are known as Pulsars.
Most stars in the universe are main sequence stars (average mass stars) which begin their life as moderately sized stars, burn their hydrogen for about 10 billion years after which they become “red giants”. Red giants form when the amount of hydrogen in an average star is lower than what is needed for fusion to continue. The outer layers of such stars expand and cool, and their helium cores contract. Over time, the outer layers are shed and the remaining helium core of the now dead star shines as a small white dwarf star. It is the remnant of the
The Big Bang, the alpha of existence for the building blocks of stars, happened approximately fourteen billion years ago. The elements produced by the big bang consisted of hydrogen and helium with trace amounts of lithium. Hydrogen and helium are the essential structure which build stars. Within these early stars, heavier elements were slowly formed through a process known as nucleosynthesis. Nucleosythesis is the process of creating new atomic nuclei from pre-existing nucleons. As the stars expel their contents, be it going supernova, solar winds, or solar explosions, these heavier elements along with other “star stuff” are ejected into the interstellar medium where they will later be recycled into another star. This physical process of galactic recycling is how or solar system's mass came to contain 2% of these heavier elements.
Brown dwarfs are objects in space that sit between the lines of being a star and a planet. This object is dim and hard to distinguish from low mass stars at the early stages of the dwarf’s life. They are often called failed stars because they start their life the same way as regular stars. However, in some stage, they just didn’t have enough mass gathered to generate the fusion-powered energy of a star. Scientists are certain that brown dwarfs are the missing link between stars and planets but the formations of dwarfs are still a mystery.
Imagine a massive celestial object in space, so densely packed with matter that nothing can ever escape it, not even light- that’s what black holes are. They are formed by large stars- stars that are way larger in size (20 times or more) than the sun. When such massive stars run out of fuel in its course, it can no longer sustain its heavy weight. They rapidly collapse causing colossal of explosions called supernova.
This type of supernova begins at the end of the life cycle of a star. The star will need to have a mass greater than the sun’s mass. This extra mass will allow for more fuel and the ability to become a supergiant. Throughout the star’s life it will burn up all of its hydrogen in the core, and once it reaches that point, it will begin to fuse heavier elements such as neon and magnesium. These processes are not good for the aging star, because as it does this it becomes harder and harder to produce even heavier elements. By the time it gets to iron, it becomes impossible to create any heavier elements. Also, because it’s been making heavy elements, the star has become heavier itself, creating a stronger gravity. But, the pressure hasn’t changed, so the heavy star collapses in order to find a new equilibrium. However, as it collapses, the temperature becomes hotter and more elements form. The star becomes hot and dense to a point where even atoms begin separating, creating separate protons and neutrons. This separation causes a decrease in pressure, and the star will collapse even quicker than it had been before. The star eventually becomes so dense that the neutrons touch each other, prohibiting further collapse. Because it is in such an unstable state, the star then expands rapidly, too rapid to stop, and matter begins to shoot into space. During this, there is a blast of energy from the core because of expansion, and it
The American scientist John Wheeler coined the phrase “black hole” in 1969 to describe a massively compact star with such a strong gravitational field that light cannot escape. When a star’s central reserve of hydrogen is depleted, the star begins to die. Gravity causes the center to contract to higher and higher temperatures, while the outer regions swell up, and the star becomes a red giant. The star then evolves into a white dwarf, where most of its matter is compressed into a sphere roughly the size of Earth. Some stars continue to evolve, and their centers contract to even higher densities and temperatures until their nuclear reserves are exhausted and only their gravitational energy remain. The core then rushes inward while the mantle explodes outward, creating neutron stars in the form of rapidly rotating pulsars. Imploding stars overwhelmed by gravity form black holes, where the core hits infinite density and becomes a singularity (some estimate it at 10^94 times the density of water).
Solar nebula is a rotating flattened disk of gas and dust in which the outer part of the disk became planets while the center bulge part became the sun. Its inner part is hot, which is heated by a young sun and due to the impact of the gas falling on the disk during its collapse. However, the outer part is cold and far below the freezing point of water. In the solar nebula, the process of condensation occurs after enough cooling of solar nebula and results in the formation into a disk. Condensation is a process of cooling the gas and its molecules stick together to form liquid or solid particles. Therefore, condensation is the change from gas to liquid. In this process, the gas must cool below a critical temperature. Accretion is the process in which the tiny condensed particles from the nebula begin to stick together to form bigger pieces. Solar nebular theory explains the formation of the solar system. In the solar nebula, tiny grains stuck together and created bigger grains that grew into clumps, possibly held together by electrical forces similar to those that make lint stick to your clothes. Subsequent collisions, if not too violent, allowed these smaller particles to grow into objects ranging in size from millimeters to kilometers. These larger objects are called planetesimals. As planetesimals moved within the disk and collide with one another, planets formed. Because astronomers have no direct way to observe how the Solar System formed, they rely heavily on computer simulations to study that remote time. Computer simulations try to solve Newton’s laws of motion for the complex mix of dust and gas that we believe made up the solar nebula. Merging of the planetesimals increased their mass and thus their gravitational attraction. That, in turn, helped them grow even more massive by drawing planetesimals into clumps or rings around the sun. The process of planets building undergoes consumption of most of the planetesimals. Some survived planetesimals form small moons, asteroids, and comets. The leftover Rocky planetesimals that remained between Jupiter and Mars were stirred by Jupiter’s gravitational force. Therefore, these Rocky planetesimals are unable to assemble into a planet. These planetesimals are known as asteroids. Formation of solar system is explained by solar nebular theory. A rotating flat disk with center bulge is the solar nebula. The outer part of the disk becomes planets and the center bulge becomes the sun.
Just recently a major discovery was found with the help of a device known as The Hubble Telescope. This telescope has just recently found what many astronomers believe to be a black hole, After being focuses on a star orbiting empty space. Several pictures of various radiation fluctuations and other diverse types of readings that could be read from that area which the black hole is suspected to be in.
Gravitational collapse begins when a star has depleted its steady sources of nuclear energy and can no longer produce the expansive force, a result of normal gas pressure, that supports the star against the compressive force of its own gravitation. As the star shrinks in size (and increases in density), it may assume one of several forms depending upon its mass. A less massive star may become a white dwarf, while a more massive one would become a supernova. If the mass is less than three times that of the sun, it will form a neutron star. However, if the final mass of the remaining stellar core is more than three solar masses, as shown by the American physicists J. Robert Oppenheimer and Hartland S. Snyder in 1939, nothing remains to prevent the star from collapsing without limit to an indefinitely small size and infinitely large density, a point called the "singularity.
...e times the mass of the sun. In this case gravity is overwhelmingly strong and is able to crush the neutron star towards zero mass. The result is a black hole with a gravitational field strong enough to not even let light escape (Brusca, 2004).
Small regions within an instellar cloud about a fraction of a light year across begin to collapse under their own gravity. As the collapse continues, the center of this core region becomes denser and denser climbing from only 100 atoms per cubic centimeter to millions of atoms per cubic centimeter and higher. As it collapses, whatever very slight rotation it originally had gets amplified so that it spins faster and faster. Although the gas falling along the axis of the collapsing cloud feels nothing more than the gravitational force of the central core, along the equator of the object, centrifugal forces due to its spinning become so strong that they strengthen the collapse along this direction. The cloud collapses into a flattened disk with ...
A star begins as nothing more than a very light distribution of interstellar gases and dust particles over a distance of a few dozen lightyears. Although there is extremely low pressure existing between stars, this distribution of gas exists instead of a true vacuum. If the density of gas becomes larger than .1 particles per cubic centimeter, the interstellar gas grows unstable. Any small deviation in density, and because it is impossible to have a perfectly even distribution in these clouds this is something that will naturally occur, and the area begins to contract. This happens because between about .1 and 1 particles per cubic centimeter, pressure gains an inverse relationship with density. This causes internal pressure to decrease with increasing density, which because of the higher external pressure, causes the density to continue to increase. This causes the gas in the interstellar medium to spontaneously collect into denser clouds. The denser clouds will contain molecular hydrogen (H2) and interstellar dust particles including carbon compounds, silicates, and small impure ice crystals. Also, within these clouds, there are 2 types of zones. There are H I zones, which contain neutral hydrogen and often have a temperature around 100 Kelvin (K), and there are H II zones, which contain ionized hydrogen and have a temperature around 10,000 K. The ionized hydrogen absorbs ultraviolet light from it’s environment and retransmits it as visible and infrared light. These clouds, visible to the human eye, have been named nebulae. The density in these nebulae is usually about 10 atoms per cubic centimeter. In brighter nebulae, there exists densities of up to several thousand atoms per cubic centimete...
Infrared technology now provides some insight on how a star is formed. Cloud cores contain sources of fierce infrared radiation, evidence of energy from collapsing protostars (potential energy converted to kinetic energy). Also, young stars are found surrounded by clouds of gas, the leftover dark molecular cloud. Young stars with warm cores usually appear in clusters, groups of stars that form from the same cloud core. We will discuss what special elements are included in molecular clouds that bring about the birth of stars.
A star's birth starts with a interstellar cloud. A interstellar cloud, or a interstellar medium, is a cloud made of hydrogen gas and dust. Also, the interstellar cloud is a filled space between the other stars, that has a rattling low density (Interstellar Medium). A star forms from a interstellar cloud by combining with other atoms. With the temperature being, nothing to just above zero degrees, the atoms of the gas' start to sick together. Then the star forms in a molecular cloud. A molecular cloud, is just a thick compact of interstellar gas and dust.