Lesson 4: Stellar Explosions and Neutron Stars
... • The triple-alpha reaction and the major carbon and oxygen burning reactions are helium capture reactions. The capture of helium nuclei continues until silicon is created, at which point the supply of helium nuclei in the star’s core is depleted: • 20Ne + 4He → 24Mg + γ • 24Mg + 4He → 28Si + γ • Fo ...
... • The triple-alpha reaction and the major carbon and oxygen burning reactions are helium capture reactions. The capture of helium nuclei continues until silicon is created, at which point the supply of helium nuclei in the star’s core is depleted: • 20Ne + 4He → 24Mg + γ • 24Mg + 4He → 28Si + γ • Fo ...
Slides - Indico
... Presently, LUNA is the world’s only underground accelerator at LNGS, Italy, with a maximal energy of Ebeam=400 keV Many accelerators have been proposed in the world, operating up to several MeV, i.e. well suited to study BBN reactions. ...
... Presently, LUNA is the world’s only underground accelerator at LNGS, Italy, with a maximal energy of Ebeam=400 keV Many accelerators have been proposed in the world, operating up to several MeV, i.e. well suited to study BBN reactions. ...
ASTR 31: Descriptive Astronomy
... Helium capture The triple-alpha reaction and the major carbon and oxygen burning reactions are helium capture reactions. The capture of helium nuclei continues until silicon is created, at which point the supply of helium nuclei in the star’s core is depleted: 20Ne + 4He → 24Mg + 24Mg + 4He ...
... Helium capture The triple-alpha reaction and the major carbon and oxygen burning reactions are helium capture reactions. The capture of helium nuclei continues until silicon is created, at which point the supply of helium nuclei in the star’s core is depleted: 20Ne + 4He → 24Mg + 24Mg + 4He ...
Origin of the Universe
... Cataclysmic expansion called a supernova (30 sec) Mass is accelerated outward Forces holding apart atomic nuclei are overcome Produces free neutrons Heavier atoms formed by neutron capture ...
... Cataclysmic expansion called a supernova (30 sec) Mass is accelerated outward Forces holding apart atomic nuclei are overcome Produces free neutrons Heavier atoms formed by neutron capture ...
Image Credit - Northwestern University
... The Answer: From the Cosmic Microwave Background (WMAP), we can intuit the percentages of normal matter, dark matter and ...
... The Answer: From the Cosmic Microwave Background (WMAP), we can intuit the percentages of normal matter, dark matter and ...
Chapter 7
... that freeze-out time the abundances of species of particles are given by their thermal equilibrium value (which changes with time as the universe cools down), while after that time the abundances stay fixed. This means that we can calculate the abundances to good approximation by finding at which te ...
... that freeze-out time the abundances of species of particles are given by their thermal equilibrium value (which changes with time as the universe cools down), while after that time the abundances stay fixed. This means that we can calculate the abundances to good approximation by finding at which te ...
1)2 A light year is a) about six trillion miles. b) the distance to the star
... a) heat within the Earth that is left over from formation and created by radioactive decay. b) heat from the sun being absorbed by the surface. c) the moon's tidal forces. 11)2 Evidence from Type I A supernovae indicates that a) our galaxy is expanding b) the local group of galaxies is expanding c) ...
... a) heat within the Earth that is left over from formation and created by radioactive decay. b) heat from the sun being absorbed by the surface. c) the moon's tidal forces. 11)2 Evidence from Type I A supernovae indicates that a) our galaxy is expanding b) the local group of galaxies is expanding c) ...
The Origin of the Universe - Christos N. Hadjichristidis
... A globular cluster is a dense collection of close to a million stars, all of which formed at roughly the same time so they can serve as cosmic clocks The fate of every star depends solely on its initial mass. So what should we look for (Corpses of massive or light stars)? The brightest of white dwar ...
... A globular cluster is a dense collection of close to a million stars, all of which formed at roughly the same time so they can serve as cosmic clocks The fate of every star depends solely on its initial mass. So what should we look for (Corpses of massive or light stars)? The brightest of white dwar ...
Document
... Unchanging situations need not be static New matter can be created spontaneously as the universe expands (a few hundred atoms per year per galaxy) Expansion of universe and creation of new matter balanced via a negative energy. The universe is constant in its overall density ...
... Unchanging situations need not be static New matter can be created spontaneously as the universe expands (a few hundred atoms per year per galaxy) Expansion of universe and creation of new matter balanced via a negative energy. The universe is constant in its overall density ...
Friday, January 27, 2017 First exam a week from today. Review
... H -> He (2 protons, 2 neutrons - Chapter 1, figure 1.6) 2 Helium -> unstable, no such element 3 Helium -> Carbon (6 protons, 6 neutrons) 4 Helium -> Oxygen (8 protons, 8 neutrons) 5 Helium -> Neon (10 protons, 10 neutrons) 6 Helium -> Magnesium (12 protons, 12 neutrons) 7 Helium -> Silicon (14 prot ...
... H -> He (2 protons, 2 neutrons - Chapter 1, figure 1.6) 2 Helium -> unstable, no such element 3 Helium -> Carbon (6 protons, 6 neutrons) 4 Helium -> Oxygen (8 protons, 8 neutrons) 5 Helium -> Neon (10 protons, 10 neutrons) 6 Helium -> Magnesium (12 protons, 12 neutrons) 7 Helium -> Silicon (14 prot ...
Assessment language for COS page…
... 42. At 10-12 seconds, the four forces finished separating. Gravity is one of those forces. What are the other three? ...
... 42. At 10-12 seconds, the four forces finished separating. Gravity is one of those forces. What are the other three? ...
Astro Review - Blank - Mayfield City Schools
... All distant galaxies are moving away from ours because our galaxy is at the center of the universe. a. true b. false 3. __c___ The _________________ states that the universe began when a dense, hot, super massive ...
... All distant galaxies are moving away from ours because our galaxy is at the center of the universe. a. true b. false 3. __c___ The _________________ states that the universe began when a dense, hot, super massive ...
AS2001
... expanding Universe occur at the following epochs: • Annihilation: particles and anti-particles annihilate, producing photons. Small excess of particles (~1 per 109 photons) • Baryogenesis: free quarks confined by strong force in (colourless) groups of 3 producing neutrons (ddu) and protons (uud). • ...
... expanding Universe occur at the following epochs: • Annihilation: particles and anti-particles annihilate, producing photons. Small excess of particles (~1 per 109 photons) • Baryogenesis: free quarks confined by strong force in (colourless) groups of 3 producing neutrons (ddu) and protons (uud). • ...
The Nuclear Fusion Reaction Inside Stars
... How is helium created? With your group discuss how nuclear fusion might happen to create helium. Diagram on dry erase board how helium is made in a star Be ready to present your idea to the class. ...
... How is helium created? With your group discuss how nuclear fusion might happen to create helium. Diagram on dry erase board how helium is made in a star Be ready to present your idea to the class. ...
What Are We Made Of? - University of Louisville
... • The Universe contains two components-matter and Structure of energy. Atoms • The three fundamental forces, the pushes and pulls in the universe are gravitational, electromagnetic and nuclear. The interaction of these three forces determines the structure of matter. • The nuclear force overpowers t ...
... • The Universe contains two components-matter and Structure of energy. Atoms • The three fundamental forces, the pushes and pulls in the universe are gravitational, electromagnetic and nuclear. The interaction of these three forces determines the structure of matter. • The nuclear force overpowers t ...
Nuclear Nomenclature
... • The production of neutrinos and the nucleosynthesis and ejection of heavy nuclei in Type II supernovae was confirmed by SN 1987a in the Large Magellenic Cloud, a nearby galaxy, on February 23, 1987. Neutrino detectors in Ohio and Japan detected a total of about 20 neutrinos even though this supern ...
... • The production of neutrinos and the nucleosynthesis and ejection of heavy nuclei in Type II supernovae was confirmed by SN 1987a in the Large Magellenic Cloud, a nearby galaxy, on February 23, 1987. Neutrino detectors in Ohio and Japan detected a total of about 20 neutrinos even though this supern ...
Stellar Nucleosynthesis
... Nucleosynthesis in Stars • Great triumphs of 20th century physics – Discovery that sun, stars are mostly H – Explanation of nuclear fusion reactions powering sun • Nuclear Binding Energy • Quantum mechanics • Weak interaction ( beta decay) ...
... Nucleosynthesis in Stars • Great triumphs of 20th century physics – Discovery that sun, stars are mostly H – Explanation of nuclear fusion reactions powering sun • Nuclear Binding Energy • Quantum mechanics • Weak interaction ( beta decay) ...
How the universe began
... • Blow up a balloon with spots all over it – all the spots get further away from each other ...
... • Blow up a balloon with spots all over it – all the spots get further away from each other ...
12.748 Lecture 2 Cosmic Abundances, Nucleosynthesis and
... (vertical axis) plotted against its apparent, surface temperature. After a few tens of thousands of years, the star has become so hot that its thermal energy exceeds the barrier between deuterium nuclei (deuterium is the heavier isotope of hydrogen, whose nucleus consists of one proton and one neutr ...
... (vertical axis) plotted against its apparent, surface temperature. After a few tens of thousands of years, the star has become so hot that its thermal energy exceeds the barrier between deuterium nuclei (deuterium is the heavier isotope of hydrogen, whose nucleus consists of one proton and one neutr ...
Where Do Chemical Elements Come From?
... Elements that are heavier than iron can be assembled within stars through the capture of neutrons—a mechanism called the “s” process. The process starts when an iron nucleus captures neutrons, thus creating new nuclei. These nuclei can be either stable, that is, they do not change, or radioactive, m ...
... Elements that are heavier than iron can be assembled within stars through the capture of neutrons—a mechanism called the “s” process. The process starts when an iron nucleus captures neutrons, thus creating new nuclei. These nuclei can be either stable, that is, they do not change, or radioactive, m ...
Document
... 1. Galaxies should be moving away as space expands. 2. Radiation from the Big bang should be detectable - now at 3 degrees Kelvin 3. The light elements H, He & Li should have been made in the first minutes of the universe. ...
... 1. Galaxies should be moving away as space expands. 2. Radiation from the Big bang should be detectable - now at 3 degrees Kelvin 3. The light elements H, He & Li should have been made in the first minutes of the universe. ...
Chapter 2 Basic Chemistry
... Origin of the Universe • According to the Big Bang Theory, immediately after the big bang, the Universe was extremely hot and made up of pure energy. There was a period of rapid expansion that caused the energy to cool and allowed sub-atomic particles, such as protons, electrons, and neutrons, to f ...
... Origin of the Universe • According to the Big Bang Theory, immediately after the big bang, the Universe was extremely hot and made up of pure energy. There was a period of rapid expansion that caused the energy to cool and allowed sub-atomic particles, such as protons, electrons, and neutrons, to f ...
