Announcements
... As the temperature decreased only electrons were left The heavier muon and tau particles stopped being created because there wasn’t enough energy density to produce them ...
... As the temperature decreased only electrons were left The heavier muon and tau particles stopped being created because there wasn’t enough energy density to produce them ...
PP and CNO-Cycle Nucleosynthesis
... 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 ...
Document
... So the spectra reveal details about the light source. We can use that same approach to study planets, stars, and galaxies. We can deduce the temperature and abundances of various chemical elements in the outer atmosphere of a star. Theorists predicted that when the universe was forming there was lit ...
... So the spectra reveal details about the light source. We can use that same approach to study planets, stars, and galaxies. We can deduce the temperature and abundances of various chemical elements in the outer atmosphere of a star. Theorists predicted that when the universe was forming there was lit ...
Stellar Notes
... since you can’t really SEE them, only their effect, its just a really solid theory. ...
... since you can’t really SEE them, only their effect, its just a really solid theory. ...
Why the Model of a Hydrogen
... [p. 283]. These elements all have even atomic numbers, they are made in the interior of supernovae9, and they are the same seven elements Harkins1 found in 1917 to comprise 99% of ordinary meteorites. Could this be a coincidence? Hardly! If all 83 elements in the Sun’s atmosphere were equal in abund ...
... [p. 283]. These elements all have even atomic numbers, they are made in the interior of supernovae9, and they are the same seven elements Harkins1 found in 1917 to comprise 99% of ordinary meteorites. Could this be a coincidence? Hardly! If all 83 elements in the Sun’s atmosphere were equal in abund ...
Geochemistry & Lab
... Neutron stars are believed to form in supernovae such as the one that formed the Crab Nebula (or check out this cool X-ray image of the nebula, from the Chandra X-ray Observatory). The stars that eventually become neutron stars are thought to start out with about 8 to 20-30 times the mass of our sun ...
... Neutron stars are believed to form in supernovae such as the one that formed the Crab Nebula (or check out this cool X-ray image of the nebula, from the Chandra X-ray Observatory). The stars that eventually become neutron stars are thought to start out with about 8 to 20-30 times the mass of our sun ...
Chemistry study guide 09
... 1. Atoms of the same element with a different number of neutrons 2. This different number f neutrons gives those atoms different Atomic masses 3. the Atomic mass of an element is based on the averages of its Isotopes. ...
... 1. Atoms of the same element with a different number of neutrons 2. This different number f neutrons gives those atoms different Atomic masses 3. the Atomic mass of an element is based on the averages of its Isotopes. ...
PDF file - Memorie della SAIt
... a fossil record of the nucleosynthesis that occurred several Gyr ago in halo AGB stars. They are dwarfs or giants, whose surface composition was polluted by the wind of an AGB companion. Then, the C and s-element enhancements are ashes of the nucleosynthesis occurred in the He-rich inter-shell of a ...
... a fossil record of the nucleosynthesis that occurred several Gyr ago in halo AGB stars. They are dwarfs or giants, whose surface composition was polluted by the wind of an AGB companion. Then, the C and s-element enhancements are ashes of the nucleosynthesis occurred in the He-rich inter-shell of a ...
Chapter 20: Stellar Evolution: The Death of Stars PowerPoint
... – Each successive fusion step produces less energy – All elements heavier than iron require energy input • Core fusion cannot produce elements heavier than iron • All heavier elements are produced by other processes ...
... – Each successive fusion step produces less energy – All elements heavier than iron require energy input • Core fusion cannot produce elements heavier than iron • All heavier elements are produced by other processes ...
The Chemical Composition of the Local Interstellar Dust
... - metal column density via Wλ ~ N(X) fij σ(λ) - chemical homogeneity of gas-phase in solar neighbourhood from many sightlines: C, O, Mg, Si, S, Fe, Zr, Kr, ... ...
... - metal column density via Wλ ~ N(X) fij σ(λ) - chemical homogeneity of gas-phase in solar neighbourhood from many sightlines: C, O, Mg, Si, S, Fe, Zr, Kr, ... ...
Document
... expanding implies the universe must have been smaller in the past than it is today. ...
... expanding implies the universe must have been smaller in the past than it is today. ...
Life Cycle of a Star
... on the order of hundreds of thousands to billions of solar masses. Most—and possibly all—galaxies are inferred to contain a supermassive black hole at their centers. In the case of the Milky Way, the SMBH is believed to correspond with the location of Sagittarius A* ...
... on the order of hundreds of thousands to billions of solar masses. Most—and possibly all—galaxies are inferred to contain a supermassive black hole at their centers. In the case of the Milky Way, the SMBH is believed to correspond with the location of Sagittarius A* ...
Chapter 10 The Deaths of Stars
... • Kind of like a trick candle on a birthday cakejust when you thought it was out, it lights ...
... • Kind of like a trick candle on a birthday cakejust when you thought it was out, it lights ...
Ch. 11 and 12 Study Guide (ANSWERS)
... 15) What is a nebula (pg. 519)? A nebula is a cloud of dust and gas in space. 16) The elements, hydrogen and helium, are the most common in nebulae. 17) What is nuclear fusion? Nuclear fusion is a reaction in which 2 atomic nuclei combine to form a large nucleus with a higher mass. Energy is release ...
... 15) What is a nebula (pg. 519)? A nebula is a cloud of dust and gas in space. 16) The elements, hydrogen and helium, are the most common in nebulae. 17) What is nuclear fusion? Nuclear fusion is a reaction in which 2 atomic nuclei combine to form a large nucleus with a higher mass. Energy is release ...
Wednesday, April 23 - Otterbein University
... • Very predictable; used as a standard candle – Estimate distances to galaxies where they occur ...
... • Very predictable; used as a standard candle – Estimate distances to galaxies where they occur ...
Nova & SuperNova - Heart of the Valley Astronomers
... Why? Think crudely about the electrons as "trying" to fit themselves into a MaxwellBoltzmann distribution, but failing because there are only so many states available in position-momentum space. Specifically, the exclusion principle limits them on the low-momentum end, so a degenerate gas will tend ...
... Why? Think crudely about the electrons as "trying" to fit themselves into a MaxwellBoltzmann distribution, but failing because there are only so many states available in position-momentum space. Specifically, the exclusion principle limits them on the low-momentum end, so a degenerate gas will tend ...
Section 2 - TeacherWeb
... include less. Look again at the large periodic table shown earlier in this section and find the square for iron. That square is reproduced in Figure 16. The first entry in the square is the number 26, the atomic number for iron. Recall that the atomic number tells you that every iron atom has 26 pr ...
... include less. Look again at the large periodic table shown earlier in this section and find the square for iron. That square is reproduced in Figure 16. The first entry in the square is the number 26, the atomic number for iron. Recall that the atomic number tells you that every iron atom has 26 pr ...
Determining the Distance to the Moon Triangulation
... Solar System formed from such "enriched" gas 4.6 billion years ago. As Milky Way ages, the abundances of elements compared to H in gas and new stars are increasing due to fusion and supernovae. ...
... Solar System formed from such "enriched" gas 4.6 billion years ago. As Milky Way ages, the abundances of elements compared to H in gas and new stars are increasing due to fusion and supernovae. ...
Information (Word Doc)
... (with a mass up to 1 1/2 times that of the Sun) Once a medium size star (such as our Sun) has reached the red giant phase, its outer layers continue to expand, but it’s core contracts, the result being that helium atoms together to form carbon. This fusion releases new energy but only for a few minu ...
... (with a mass up to 1 1/2 times that of the Sun) Once a medium size star (such as our Sun) has reached the red giant phase, its outer layers continue to expand, but it’s core contracts, the result being that helium atoms together to form carbon. This fusion releases new energy but only for a few minu ...
The woman who dissected the Sun
... The connection with hot bodies like stars was made in 1920 by an Indian physicist called Meghnad Saha who combined quantum theory with the theory of heat - thermodynamics. Collisions between atoms in a gas could also knock out electrons and the "Saha equation" predicted, for any temperature and dens ...
... The connection with hot bodies like stars was made in 1920 by an Indian physicist called Meghnad Saha who combined quantum theory with the theory of heat - thermodynamics. Collisions between atoms in a gas could also knock out electrons and the "Saha equation" predicted, for any temperature and dens ...
Click here - Noadswood Science
... • Fusion only occurs in a stars core, no Hydrogen is converted to Helium in the outer layer • The more massive the star, the faster the process of fusion works (higher temperature and pressure in the core); • In generating heat via fusion, the mass of the star stays roughly the same (unlike a fire w ...
... • Fusion only occurs in a stars core, no Hydrogen is converted to Helium in the outer layer • The more massive the star, the faster the process of fusion works (higher temperature and pressure in the core); • In generating heat via fusion, the mass of the star stays roughly the same (unlike a fire w ...
Howell Exam 1 Review Outline
... Structure of atoms and nuclei Components of the atom: nucleus and electrons Components of the nucleus: protons and neutrons Role of the nuclear strong force, nuclear weak force, and Coulomb (electrical) force in determining stability of nucleus (and in fusion and radioactive decay reactions) Types o ...
... Structure of atoms and nuclei Components of the atom: nucleus and electrons Components of the nucleus: protons and neutrons Role of the nuclear strong force, nuclear weak force, and Coulomb (electrical) force in determining stability of nucleus (and in fusion and radioactive decay reactions) Types o ...
Integrative Studies 410 Our Place in the Universe
... can be used as cosmic yardsticks • k: Cepheid stars oscillate between two states: In one of the states, the star is compact and large temperature and pressure gradients build up in the star. These large pressures cause the star to expand. When the star is in its expanded state, there is a much weake ...
... can be used as cosmic yardsticks • k: Cepheid stars oscillate between two states: In one of the states, the star is compact and large temperature and pressure gradients build up in the star. These large pressures cause the star to expand. When the star is in its expanded state, there is a much weake ...
The Universe and Big Bang Theory Review Sheet
... - gravity causes the gas and dust clouds to clump up, forming larger balls of gas and dust molecules. 9. A star is born how? (step 3 in Star Origin notes) -When the mass becomes slightly larger than Jupiter, the gravitational contraction causes enough high temp and high pressure to start Nuclear Fus ...
... - gravity causes the gas and dust clouds to clump up, forming larger balls of gas and dust molecules. 9. A star is born how? (step 3 in Star Origin notes) -When the mass becomes slightly larger than Jupiter, the gravitational contraction causes enough high temp and high pressure to start Nuclear Fus ...
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.