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Q.11) “The Model of the Sun” is a theoretical description of the Sun’s interior derived from calculations based on the laws of physics. It also explains how the energy from nuclear fusion in the Sun’s core gets to its photosphere. (DTU 10ED Page 329)
Q.14) There are 6 regions that have their own physical characteristics. These regions are the fusion core, radiation shell, convection shell, photosphere, chromosphere and corona. The fusion core is the region which is where the process of nuclear fusion takes places and generates energy. The radiation shell is the region where radiation flow causes energy transport. Convection shell is the region where transport of energy takes place with the help of convection cells. Photosphere surface
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They can extend to 1000 solar radius. Giant stars are smaller in size and colder than supergiant stars. (DTU 10ED Page: 354)
Q.19) The difference occurs in physical terms. In type ii supernovae, collapse of a massive star takes place. While Type ia supernovae is caused by a white dwarf star that accretes mass enough to surpass the Chandrasekhar limit resulting in a collapse into the neutron star. (DTU 10ED Page: 411 and 414)
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Q.2) A (DTU 10TH ED Page: 521)
Q.4) A star in a close binary that transforms into a black hole causes all outward pressures on a collapsing star to fail in stopping its inward motion. (DTU 10TH ED Page: 441)
Q.8) Non- rotating black holes are known as Schwarzschild black holes which collapse to a point of infinite density at its center. The rest of the volume from the event horizon to the singularity of a Schwarzchild black hole is empty space. While on the other hand, rotating black holes known as Kerr black holes spin thousands of times every second which are faster than pulsars. They also contain a donut shaped region called the ergoregion which is just outside the event horizon. Objects never remain at rest at this particular region. (DTU 10ED Page:
The main idea for paragraphs 6-8 in When Stars Explode is how stars do explode. Here are some details: according to the text,“But these nuclear reactions do not make as much energy as hydrogen did. Within a few million years, the star has nothing left." The text also said “So the star's center collapses, scrunching itself into a small, dense object. Meanwhile, the star's outer layer shoots into space at millions of miles per hour. The star has exploded!"
Some limitations are that parallax angles of less than 0.001 arcsec are very difficult to measure from Earth because of the effects on the Earth’s atmosphere. This limits Earth based telescopes to measuring the distances to stars about 10.01 or 100 parsecs away. Spaced based telescopes can get accuracy to 0.001, which has increased the number of stars whose distance could be measured with this method. However, most stars even in our own galaxy are much further away than 1000 parsecs, since the Milky Way is about 30,000 parsecs across.
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
On the other end of the spectrum, the death of a super-massive star is one of the most brilliant displays of pure power in the universe which includes an amazing light show which has no equal. A super-massive star is exactly what it sounds like, a star so big that it dwarfs our own star in every way. When a super-massive sun begins to run out of out of hydrogen it begins to collapse, but due to its immense gravity and size, the collapse produces such an abrupt implosion that the last remnants of nuclear fusion remaining push all the mass of the star back out into space (Britt, 2007). This can be compared to someone jumping onto a trampoline whose elastic has enough elasticity to force one back into the air. This occurrence is known as a supernova explosion, which is the largest explosion in the known universe. A supernova explosion can even be seen from other galaxies, as scientists have done witnessed from observations using the Hubble telescope. The star is so big, however, that it only blows its outer atmosphere away, still leaving a massive amount of matter that is doomed to collapse again, and this time it will be a one-way ticket to oblivion. The super-massive star finally collapses and its own incredible mass crushes it’s internally and now turns it into a neutron star. An average neutron star is about ten miles in diameter, or the size of Manhattan. Although this
2) The force that causes a neutron star not collapse further is called Neutron degeneracy pressure. When a white dwarf reaches a mass greater than the Chandrasekhar limit the electron degeneracy pressure is no longer strong enough to prevent further collapse. Neutron degeneracy is more powerful than electron degeneracy and can withstand greater pressure. Neutron degeneracy refers to the principle that two neutrons cannot occupy the same space and therefore have a repulsive force on each other.
The only stars that are within the ten light year radius are Proxima Centauri,Proxima Centauri,Luhman 16,WISE 0855−0714,Wolf 359,Lalande 21185,Sirius,Luyten 726-8, and Ross 154 with are all way too small to create a supernova. In fact the closest star that could create a supernova is Betelgeuse which is 430 light years away all it will do is shine a little brighter for a couple weeks.
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.
Although the basic formation process is understood, one perennial mystery in the science of black holes is that they appear to exist on two radically different size scales. On the one end, there are the countless black holes that are the remnants of massive stars. Peppered throughout the Universe, these "stellar mass" black holes are generally 10 to 24 times as massive as the Sun. Astronomers spot them when another star draws near enough for some of the matter surrounding it to be snared by the black hole 's gravity, churning out x-rays in the process. Most stellar black holes, however, lead isolated lives and are impossible to detect. Judging from the number of stars large enough to produce such black holes, however, scientists estimate that there are as many as ten million to a billion such black holes in the Milky
Mysteries of black holes always unknown as in where they come from. “Black holes form when the center of a massive star collapses in on itself.” When this occurs, it causes a supernova. A supernova is a star that increases greatly in brightness because of a catastrophic explosion that ejects most of its mass. The parts left over from the supernova collapse in onto itself forming a black hole. This well-known black hole is called a stellar mass black hole. “Scientists believe supermassive black holes have formed at
A blackhole occurs when a giant or supergiant start dies. But before the star dies their is a fusion reaction going on constantly throughout its life time. This fusion reaction can be di erent from star to star ff depending on its age. For a young star the reaction is a proton to proton fusion, a middle aged star can have a carbon reaction and a much older star, which is collapsing on itself has a helium fusion reaction. Once a star has finished reacting all of the helium it has the core begins to 'eat' it's self instead of the helium. This makes the core have a stronger and stronger gravitational pull. After the core has 'eaten or suck up everything into its fusion reaction it collapses due to so much compressed mass in a small space which forms a giant explosion creating a supernova which then turns into a singularity. Thus
The average star, however becomes a red star when the hydrogen fuel at the center is exhausted. When the hydrogen is exhausted, a shell of nuclear reactions will move outwards, expanding and cooling, turning to red, henceforth the red giant star. When a star of a larger caliber, they will become a red supergiant star. While in this phase, the star’s nuclear fusion will use helium as fuel over hydrogen as it previously did. Helium is quickly used causing the star to shrink and turn blue temporarily before exhausting most of its helium supply and turning red once
A stellar black hole is formed when a gianormous star collapses upon itself. When a stellar black hole forms, a supernova, or an exploding star is created as well. This supernova releases that rest of the exploding star into space. As a result a stellar black hole is created. Once a stellar black hole is created, they can be up to 20 times bigger than the
Stellar black holes are formed from certain dying stars. According to Brian Dunbar from NASA, if a very large dying star runs out of nuclear fuel it will cause an explosion called a supernova. This causes the star's gravity to collapse on itself and form a stellar black hole. When the supernova occurs, the outer layers of the star are blasted away leaving just the core. (“HubbleSite - Reference Desk”) This creates a black hole because the gravity of the star compresses the core into such a small area where gravity is incredibly strong. Stars do have to be a certain size to become a black hole though. Stars have to be at least about 20 times the size of our sun to form a black hole when it dies. (“HubbleSite - Reference Desk”) This means even if the sun does die out it won't become a black hole. Also, there aren’t any large stars close enough to Earth that could become a black hole and
In our physical world, there are a multitude of phenomenon that occur daily that we experience that often go unnoticed. It contains a vast array of conceptual applications and the equations applied to them in order to better explain and calculate the phenomenon involved. In a normal occurrence an individual can explain and calculate certain aspects of movement and processes that are also involved with it. When dealing with the transferring of heat and various process related to heat, the terms convection, conduction and radiation are frequently discussed thoroughly. The overall field of thermodynamics involves the study of thermal processes in physical systems. Some terms involved with these particular concepts include: closed system, empirical law, free energy, joule’s law, specific, temperature, and thermodynamics. The general defined term of convection is “the heat transfer by mass motion of a fluid such as air or water when the heated fluid is caused to move away from the source of heat, carrying energy with it” (Georgia State University). “In the world of physics, the term conduction is usually defined as a form of heat transfer by the way of molecular tension inside an object or material that does not show any individual motion in its entirety” (Georgia State University). Radiation by means of physics related terms is defined as “the emission or transmission of energy in the form of waves or particles through 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