Stars go through a life cycle. Some stars will finish their life cycle as
... The energy released from the nuclear fuel is used to heat water. The water turns into ............................................... and this is used to drive a ............................................... . This turns a ............................................... to produce electricity. ...
... The energy released from the nuclear fuel is used to heat water. The water turns into ............................................... and this is used to drive a ............................................... . This turns a ............................................... to produce electricity. ...
1 Origin of the Elements. Isotopes and Atomic Weights
... in much of the stellar material being ejected into space, where it becomes incorporated together with further hydrogen and helium in the next generation of stars. It should be noted, however, that, as iron is at the maximum of the nuclear binding energy curve, only those elements up to iron (Z D 26) ...
... in much of the stellar material being ejected into space, where it becomes incorporated together with further hydrogen and helium in the next generation of stars. It should be noted, however, that, as iron is at the maximum of the nuclear binding energy curve, only those elements up to iron (Z D 26) ...
Unit P1 - Universal Physics 2
... Some scientists have explained that red shift can actually be used to support the Big Bang Theory – this explanation is based around the rates of expansion and contraction of different galaxies. If our neighbouring galaxy is expanding at a different rate to the Milky Way then it will appear ...
... Some scientists have explained that red shift can actually be used to support the Big Bang Theory – this explanation is based around the rates of expansion and contraction of different galaxies. If our neighbouring galaxy is expanding at a different rate to the Milky Way then it will appear ...
Lecture notes 11
... the pp-chain dominates. In higher-mass stars (with enough heavy metals), the CNO process will dominate. For very low mass stars, the central temperature will diminish to the point where no nuclear fusion occurs. For a star with Solar compositions this is 0.072 M⊙. For very high mass stars, (>90 M⊙), ...
... the pp-chain dominates. In higher-mass stars (with enough heavy metals), the CNO process will dominate. For very low mass stars, the central temperature will diminish to the point where no nuclear fusion occurs. For a star with Solar compositions this is 0.072 M⊙. For very high mass stars, (>90 M⊙), ...
Titelseite
... universe come from? • Generally speaking, all elements that have a mass number higher than 4 must be generated in stars. The fusion process works well (exothermic) up to a mass number of roundabout 60. • Heavier elements can only be generated with the help of neutron currents, whereby we differentia ...
... universe come from? • Generally speaking, all elements that have a mass number higher than 4 must be generated in stars. The fusion process works well (exothermic) up to a mass number of roundabout 60. • Heavier elements can only be generated with the help of neutron currents, whereby we differentia ...
Star Formation in the Local Milky Way
... attempt to determine the IMF was by Salpeter (1955) more than half a century ago. He derived the IMF from the luminosity function of local field stars (i.e., stars within ∼ 500 pc of the sun) by converting stellar luminosities to masses using empirical massluminosity relations. He corrected for loss ...
... attempt to determine the IMF was by Salpeter (1955) more than half a century ago. He derived the IMF from the luminosity function of local field stars (i.e., stars within ∼ 500 pc of the sun) by converting stellar luminosities to masses using empirical massluminosity relations. He corrected for loss ...
The Sun and Stars 4.1 Energy formation and layers of the Sun 4.2
... Technology has not advanced far enough for us to travel even close to the speed of light. Nor has anything been identified that can travel at this speed other than the photons of light energy. Though it is easy to believe that the light from stars reaches us "instantaneously," like that of a light b ...
... Technology has not advanced far enough for us to travel even close to the speed of light. Nor has anything been identified that can travel at this speed other than the photons of light energy. Though it is easy to believe that the light from stars reaches us "instantaneously," like that of a light b ...
Observing Stellar Evolution
... molecular cloud) and you are willing to wait a sufficiently long time you will see this material condense into new stars. When this condensation occurs, the gas gets hot enough to begin nuclear fusion. This occurs at about 10 million degrees K. It is important to distinguish between nebulae that are ...
... molecular cloud) and you are willing to wait a sufficiently long time you will see this material condense into new stars. When this condensation occurs, the gas gets hot enough to begin nuclear fusion. This occurs at about 10 million degrees K. It is important to distinguish between nebulae that are ...
Neutron Stars, first class
... what was then the fate of more massive stars. In 1931/1932 Landau proposed that this fate would be an object “where the atomic nuclei were so close to each other to form a gigantic nucleus” ...
... what was then the fate of more massive stars. In 1931/1932 Landau proposed that this fate would be an object “where the atomic nuclei were so close to each other to form a gigantic nucleus” ...
Energy transport in stellar interiors
... generation will be treated in Ch. 5. • Heat can be removed by the release of energetic neutrinos, which escape from the stellar interior without interaction. Neutrinos are released as a by-product of some nuclear reactions, in which case they are often accounted for in ǫnuc . But neutrinos can also ...
... generation will be treated in Ch. 5. • Heat can be removed by the release of energetic neutrinos, which escape from the stellar interior without interaction. Neutrinos are released as a by-product of some nuclear reactions, in which case they are often accounted for in ǫnuc . But neutrinos can also ...
Early stages of clustered star formation -massive dark clouds
... clouds, from the giant cloud complexes to the small, gravitationally unstable cores. These different appearances are primarily described by their diversity in size, mass and density. A spontaneous or triggered collapse of the densest parts of molecular clouds initiates the process of star formation. ...
... clouds, from the giant cloud complexes to the small, gravitationally unstable cores. These different appearances are primarily described by their diversity in size, mass and density. A spontaneous or triggered collapse of the densest parts of molecular clouds initiates the process of star formation. ...
ph600-12 - University of Kent
... The project will be based on an aspect of: How do stars like the Sun form? ...
... The project will be based on an aspect of: How do stars like the Sun form? ...
White Dwarf Stars - Stellar Physics Department
... DZ stars are helium-rich and show metal lines, for example the most commonly detected metals are Ca, Na, Mg, and Fe. Some white dwarfs display a combination of the above mentioned spectral features and therefore all need to be used. For example a white dwarf showing Balmer lines and Ca II lines woul ...
... DZ stars are helium-rich and show metal lines, for example the most commonly detected metals are Ca, Na, Mg, and Fe. Some white dwarfs display a combination of the above mentioned spectral features and therefore all need to be used. For example a white dwarf showing Balmer lines and Ca II lines woul ...
Chap4-Timing
... Fate of planetary systems during the red giant phase. All planets within the final extent of the red giant envelope will be engulfed and migrate inwards. Planets further out will have greater chance of survival, migrating outwards as mass is lost from central star. In mass is loss instantane ...
... Fate of planetary systems during the red giant phase. All planets within the final extent of the red giant envelope will be engulfed and migrate inwards. Planets further out will have greater chance of survival, migrating outwards as mass is lost from central star. In mass is loss instantane ...
What is the minimum size of a star that will go supernova? A. Half
... A. Very polite motion from a star B. Angular change in position by a star as seen from Earth C. The correct motion of a star Answer: B. The angular change in position by a star as seen from Earth. Stars appear to have fixed positions on the sky. That’s one reason why the constellations are ...
... A. Very polite motion from a star B. Angular change in position by a star as seen from Earth C. The correct motion of a star Answer: B. The angular change in position by a star as seen from Earth. Stars appear to have fixed positions on the sky. That’s one reason why the constellations are ...
Determining the Origin of Inner Planetary System Debris Orbiting the
... of the stellar system, and tloss is the timescale of the dominant dust removal mechanism operating in the disk. The value used for tag e typically should be the best measured stellar age available, as in the case of ζ Leporis (tag e = 300 Myr; Chen & Jura 2001). However, in the case of young stars w ...
... of the stellar system, and tloss is the timescale of the dominant dust removal mechanism operating in the disk. The value used for tag e typically should be the best measured stellar age available, as in the case of ζ Leporis (tag e = 300 Myr; Chen & Jura 2001). However, in the case of young stars w ...
white dwarfs and the age of the universe
... During the crystallization process, the equilibrium chemical compositions of the solid and liquid plasmas are not equal. Therefore, if the resulting solid is denser than the liquid mixture, it sink towards the central region. If they are lighter, they rise upwards and melt when the solidification te ...
... During the crystallization process, the equilibrium chemical compositions of the solid and liquid plasmas are not equal. Therefore, if the resulting solid is denser than the liquid mixture, it sink towards the central region. If they are lighter, they rise upwards and melt when the solidification te ...
First firm spectral classification of an early-B PMS star
... show a red continuum, most likely due to hot dust, and an emission line spectrum that includes Brγ and, often, CO 2.3 µm bandhead emission. The latter emission can be modeled as being produced by a Keplerian rotating disk surrounding the young, potentially massive star (Bik & Thi 2004; Blum et al. 2 ...
... show a red continuum, most likely due to hot dust, and an emission line spectrum that includes Brγ and, often, CO 2.3 µm bandhead emission. The latter emission can be modeled as being produced by a Keplerian rotating disk surrounding the young, potentially massive star (Bik & Thi 2004; Blum et al. 2 ...
Type II supernova
A Type II supernova (plural: supernovae or supernovas) results from the rapid collapse and violent explosion of a massive star. A star must have at least 8 times, and no more than 40–50 times, the mass of the Sun (M☉) for this type of explosion. It is distinguished from other types of supernovae by the presence of hydrogen in its spectrum. Type II supernovae are mainly observed in the spiral arms of galaxies and in H II regions, but not in elliptical galaxies.Stars generate energy by the nuclear fusion of elements. Unlike the Sun, massive stars possess the mass needed to fuse elements that have an atomic mass greater than hydrogen and helium, albeit at increasingly higher temperatures and pressures, causing increasingly shorter stellar life spans. The degeneracy pressure of electrons and the energy generated by these fusion reactions are sufficient to counter the force of gravity and prevent the star from collapsing, maintaining stellar equilibrium. The star fuses increasingly higher mass elements, starting with hydrogen and then helium, progressing up through the periodic table until a core of iron and nickel is produced. Fusion of iron or nickel produces no net energy output, so no further fusion can take place, leaving the nickel-iron core inert. Due to the lack of energy output allowing outward pressure, equilibrium is broken.When the mass of the inert core exceeds the Chandrasekhar limit of about 1.4 M☉, electron degeneracy alone is no longer sufficient to counter gravity and maintain stellar equilibrium. A cataclysmic implosion takes place within seconds, in which the outer core reaches an inward velocity of up to 23% of the speed of light and the inner core reaches temperatures of up to 100 billion kelvin. Neutrons and neutrinos are formed via reversed beta-decay, releasing about 1046 joules (100 foes) in a ten-second burst. The collapse is halted by neutron degeneracy, causing the implosion to rebound and bounce outward. The energy of this expanding shock wave is sufficient to accelerate the surrounding stellar material to escape velocity, forming a supernova explosion, while the shock wave and extremely high temperature and pressure briefly allow for theproduction of elements heavier than iron. Depending on initial size of the star, the remnants of the core form a neutron star or a black hole. Because of the underlying mechanism, the resulting nova is also described as a core-collapse supernova.There exist several categories of Type II supernova explosions, which are categorized based on the resulting light curve—a graph of luminosity versus time—following the explosion. Type II-L supernovae show a steady (linear) decline of the light curve following the explosion, whereas Type II-P display a period of slower decline (a plateau) in their light curve followed by a normal decay. Type Ib and Ic supernovae are a type of core-collapse supernova for a massive star that has shed its outer envelope of hydrogen and (for Type Ic) helium. As a result, they appear to be lacking in these elements.