Origin of gold found in rare neutron
... the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. The elements on Earth are all of cosmic origin. Carbon and oxygen atoms in our bodies, for example, come from the interior of stars, where they were formed under high pressure and heat. They were later spewed into the universe in su ...
... the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. The elements on Earth are all of cosmic origin. Carbon and oxygen atoms in our bodies, for example, come from the interior of stars, where they were formed under high pressure and heat. They were later spewed into the universe in su ...
Intro to Cosmology!
... of particles, talk about quantum properties of Space-Time. Superpartners exist in separate quantum Space-Time coordinates called “Superspace.” The existence of a superspace simplifies QFT significantly. General Relativity can be derived from the theory of Supersymmetry. Predicts the energy level of ...
... of particles, talk about quantum properties of Space-Time. Superpartners exist in separate quantum Space-Time coordinates called “Superspace.” The existence of a superspace simplifies QFT significantly. General Relativity can be derived from the theory of Supersymmetry. Predicts the energy level of ...
Origin of the Elements and Atomic Structure
... Star Formation by Condensation • Stars form by the gravitational condensation of hydrogen clouds. • High temperatures and pressures allow nuclear fusion of light element nuclei. Star formation in Orion Nebula (NASA, Hubble) ...
... Star Formation by Condensation • Stars form by the gravitational condensation of hydrogen clouds. • High temperatures and pressures allow nuclear fusion of light element nuclei. Star formation in Orion Nebula (NASA, Hubble) ...
9. The very beginning - Mullard Space Science Laboratory
... 9. The beginning • This short lecture: • The hot big bang • Timeline –10-43 seconds to 380,000 years. ...
... 9. The beginning • This short lecture: • The hot big bang • Timeline –10-43 seconds to 380,000 years. ...
ASTRONOMY 157 – Stars and Galaxies - Syllabus
... Office hours: 1-2:15 Tue and Th, Cook 514 We will derive details only mentioned in Astr 005 with algebra and basic geometry, appropriate for non-science majors. Most class slides will be posted on UVM Blackboard. ...
... Office hours: 1-2:15 Tue and Th, Cook 514 We will derive details only mentioned in Astr 005 with algebra and basic geometry, appropriate for non-science majors. Most class slides will be posted on UVM Blackboard. ...
Unit 2 Review Guide
... 11. What color would galaxies shift towards if they were moving towards us? 12. What is the name of the cluster that our galaxy is in? 13. What are 2 possibilities for the ultimate fate of the universe? 14. What is a nebula? 15. What force causes stars to form? 16. What do we call a beginning star t ...
... 11. What color would galaxies shift towards if they were moving towards us? 12. What is the name of the cluster that our galaxy is in? 13. What are 2 possibilities for the ultimate fate of the universe? 14. What is a nebula? 15. What force causes stars to form? 16. What do we call a beginning star t ...
printer-friendly version of benchmark
... The fusion of hydrogen into helium constitutes what astronomers call the star’s “main sequence” lifetime – roughly analogous to a person’s middle age. The length of this lifetime is related to the star’s mass, although not in the way one might imagine. The most massive stars undergo fusion at an ext ...
... The fusion of hydrogen into helium constitutes what astronomers call the star’s “main sequence” lifetime – roughly analogous to a person’s middle age. The length of this lifetime is related to the star’s mass, although not in the way one might imagine. The most massive stars undergo fusion at an ext ...
Prof. Kenney C lass 8 September 26, 2016
... star during normal stellar evolution get locked into neutron star or black hole core ...
... star during normal stellar evolution get locked into neutron star or black hole core ...
Origins of the Universe
... us the more it is red shifted • The only explanation for that is if everything is moving away from us. • This means the universe is expanding ...
... us the more it is red shifted • The only explanation for that is if everything is moving away from us. • This means the universe is expanding ...
here
... (a) The Special Theory of Relativity. (b) The Big Bang. (c) The theory of Inflation. (d) Both (b) and (c). 2. Astronomers use the fact that atoms have quantized energy levels to: (a) Determine the elemental abundances of stars and other astrophysical bodies. (b) Measure the mass of stars and other a ...
... (a) The Special Theory of Relativity. (b) The Big Bang. (c) The theory of Inflation. (d) Both (b) and (c). 2. Astronomers use the fact that atoms have quantized energy levels to: (a) Determine the elemental abundances of stars and other astrophysical bodies. (b) Measure the mass of stars and other a ...
Lec10_2D
... The Death of a High Mass Star When the star’s core turns to iron, it again collapses. The increased pressure and temperature then causes iron to fuse. However… The products of iron fusion weigh more than the initial iron nucleus. According to E = m c2, this means that iron fusion does not make ener ...
... The Death of a High Mass Star When the star’s core turns to iron, it again collapses. The increased pressure and temperature then causes iron to fuse. However… The products of iron fusion weigh more than the initial iron nucleus. According to E = m c2, this means that iron fusion does not make ener ...
chap11 (WP)
... temperatures 12C begins to burn with itself, and the photons present have sufficient energy that they can cause protons and neutrons to split off from nuclei. These very high temperature reactions occur at temperatures exceeding 109 o K, and occur on a very short time scale, on the order of years in ...
... temperatures 12C begins to burn with itself, and the photons present have sufficient energy that they can cause protons and neutrons to split off from nuclei. These very high temperature reactions occur at temperatures exceeding 109 o K, and occur on a very short time scale, on the order of years in ...
Origin of the Chemical Elements
... Universe increased exponentially. This is called inflationary epoch. The wavelength of any physical object is redshifted in proportion with the global scale. Therefore, at a certain moment fluctuations with a wavelength bigger than the horizon were ‗felt‘ as constant fields and did not influence any ...
... Universe increased exponentially. This is called inflationary epoch. The wavelength of any physical object is redshifted in proportion with the global scale. Therefore, at a certain moment fluctuations with a wavelength bigger than the horizon were ‗felt‘ as constant fields and did not influence any ...
Kinetics and Numerical Modeling of Competitive Fusion Processes
... the relevant thermonuclear reactions studied in astrophysics are exothermic; the energy of particles in the exit channel is much greater than in the entrance channel (if the converse of this statement were true, perhaps there would be no humans alive today to discuss it!). The exothermic nature of r ...
... the relevant thermonuclear reactions studied in astrophysics are exothermic; the energy of particles in the exit channel is much greater than in the entrance channel (if the converse of this statement were true, perhaps there would be no humans alive today to discuss it!). The exothermic nature of r ...
The lifes of a star
... Recall that all atoms are made of a very dense and small nucleus which is positively charged and a bunch of electrons, which are negatively charged, and which surround the nucleus. At the center of the stars temperatures as very high (at least a few million degrees Celsius); pressures are also high ...
... Recall that all atoms are made of a very dense and small nucleus which is positively charged and a bunch of electrons, which are negatively charged, and which surround the nucleus. At the center of the stars temperatures as very high (at least a few million degrees Celsius); pressures are also high ...
Slides on Big Bang nucleosynthesis
... Also, lower density, lower collision rates, D burning incomplete, more D. Conversely, higher baryon/photon ratio -> more He and less D. Photon density is well known, but baryon density is not. à The measured D abundance constrains the baryon density!! A very important constraint. Ω ≈ 0.04 b ...
... Also, lower density, lower collision rates, D burning incomplete, more D. Conversely, higher baryon/photon ratio -> more He and less D. Photon density is well known, but baryon density is not. à The measured D abundance constrains the baryon density!! A very important constraint. Ω ≈ 0.04 b ...
Death of Stars with the Mass of 0.3
... A star gets its energy by fusing hydrogen to helium. The fusion creates a radiation pressure that antagonizes the gravitation which causes the star to be stable. However, once the hydrogen in the core runs out, the star begins to fuse helium to carbon and oxygen. Because of the high pressure, the st ...
... A star gets its energy by fusing hydrogen to helium. The fusion creates a radiation pressure that antagonizes the gravitation which causes the star to be stable. However, once the hydrogen in the core runs out, the star begins to fuse helium to carbon and oxygen. Because of the high pressure, the st ...
Nucleosynthesis in asymptotic giant branch stars
... in case of initial solar-like metallicity, but it could as low as 2 M¯ for zero initial metallicity ([7]. The HBB is very sensitive to mass loss by stellar wind which can reduce the mass of the envelope so that the HBB will be shut off. The temperature required for HBB is at least 107 K, which means ...
... in case of initial solar-like metallicity, but it could as low as 2 M¯ for zero initial metallicity ([7]. The HBB is very sensitive to mass loss by stellar wind which can reduce the mass of the envelope so that the HBB will be shut off. The temperature required for HBB is at least 107 K, which means ...
Stars and Black Holes: Stars A star is a massive, luminous ball of
... There are _____________ of galaxies in the ______________. Galaxies are ________________: they contain ________, ___________, and _______. The farthest galaxies and the stars we see shining in them may be also the _____________ because it takes the _____________ so long to reach us. ...
... There are _____________ of galaxies in the ______________. Galaxies are ________________: they contain ________, ___________, and _______. The farthest galaxies and the stars we see shining in them may be also the _____________ because it takes the _____________ so long to reach us. ...
12. Nuclear Reactions in Nature
... were created by a variety of nuclear processes in massive stellar systems. These massive objects exert large gravitational forces and so one might expect the new materials to remain in the stars. The ...
... were created by a variety of nuclear processes in massive stellar systems. These massive objects exert large gravitational forces and so one might expect the new materials to remain in the stars. The ...
Notes - Michigan State University
... • Used a deuterium beam on a 11B target to produce 12B via a (d,p) reaction. • 12B b-decays within 20 ms into the second excited state in 12C • This state then immediately decays under alpha emission into 8Be • Which immediately decays into 2 alpha particles So they saw after the delay of the b-deca ...
... • Used a deuterium beam on a 11B target to produce 12B via a (d,p) reaction. • 12B b-decays within 20 ms into the second excited state in 12C • This state then immediately decays under alpha emission into 8Be • Which immediately decays into 2 alpha particles So they saw after the delay of the b-deca ...
The Stellar Cycle
... What holds the white dwarf from collapsing? • The resulting outward pressure which keeps the electrons apart is called electron degeneracy pressure – this is what balances the weight. • Only if more energy drives the electrons into higher energy states, can the density increase. • Adding mass can d ...
... What holds the white dwarf from collapsing? • The resulting outward pressure which keeps the electrons apart is called electron degeneracy pressure – this is what balances the weight. • Only if more energy drives the electrons into higher energy states, can the density increase. • Adding mass can d ...
Nucleosynthesis
Nucleosynthesis is the process that creates new atomic nuclei from pre-existing nucleons, primarily protons and neutrons. The first nuclei were formed about three minutes after the Big Bang, through the process called Big Bang nucleosynthesis. It was then that hydrogen and helium formed to become the content of the first stars, and this primeval process is responsible for the present hydrogen/helium ratio of the cosmos.With the formation of stars, heavier nuclei were created from hydrogen and helium by stellar nucleosynthesis, a process that continues today. Some of these elements, particularly those lighter than iron, continue to be delivered to the interstellar medium when low mass stars eject their outer envelope before they collapse to form white dwarfs. The remains of their ejected mass form the planetary nebulae observable throughout our galaxy.Supernova nucleosynthesis within exploding stars by fusing carbon and oxygen is responsible for the abundances of elements between magnesium (atomic number 12) and nickel (atomic number 28). Supernova nucleosynthesis is also thought to be responsible for the creation of rarer elements heavier than iron and nickel, in the last few seconds of a type II supernova event. The synthesis of these heavier elements absorbs energy (endothermic) as they are created, from the energy produced during the supernova explosion. Some of those elements are created from the absorption of multiple neutrons (the R process) in the period of a few seconds during the explosion. The elements formed in supernovas include the heaviest elements known, such as the long-lived elements uranium and thorium.Cosmic ray spallation, caused when cosmic rays impact the interstellar medium and fragment larger atomic species, is a significant source of the lighter nuclei, particularly 3He, 9Be and 10,11B, that are not created by stellar nucleosynthesis.In addition to the fusion processes responsible for the growing abundances of elements in the universe, a few minor natural processes continue to produce very small numbers of new nuclides on Earth. These nuclides contribute little to their abundances, but may account for the presence of specific new nuclei. These nuclides are produced via radiogenesis (decay) of long-lived, heavy, primordial radionuclides such as uranium and thorium. Cosmic ray bombardment of elements on Earth also contribute to the presence of rare, short-lived atomic species called cosmogenic nuclides.