P-process nucleosynthesis in detonating white dwarfs in the light of
... shock wave is formed which rapidly transforms into a detonation due to the fast and energetic nuclear combustion developed at the rear edge of the shock wave. Soon a ChapmannJouguet self-sustained detonation emerged (see for instance Fig. 4 of GSBW). During its journey the substrate of the detonatio ...
... shock wave is formed which rapidly transforms into a detonation due to the fast and energetic nuclear combustion developed at the rear edge of the shock wave. Soon a ChapmannJouguet self-sustained detonation emerged (see for instance Fig. 4 of GSBW). During its journey the substrate of the detonatio ...
The Search for New “r-process-Enhanced” Metal
... Nature’s Gift to Nuclear Astrophysics • There now exists a small number of very metal-poor stars ([Fe/H] < -2.0) which have been discovered recently that exhibit strong enhancements in their ratios of r-process elements, compared with the Sun • r-I: 0.3 < [r-process/Fe] < 1.0 (~ 10 known) • r-II: 1 ...
... Nature’s Gift to Nuclear Astrophysics • There now exists a small number of very metal-poor stars ([Fe/H] < -2.0) which have been discovered recently that exhibit strong enhancements in their ratios of r-process elements, compared with the Sun • r-I: 0.3 < [r-process/Fe] < 1.0 (~ 10 known) • r-II: 1 ...
Acceleration of Coronal Mass Ejection In Long Rising Solar
... • The product at the core is a neutral star, or even a black hole (if the degenerate pressure of neutrons can not withhold the gravitational pressure) • Heavy elements generated in the core collapse are send into the interstellar space through the explosion ...
... • The product at the core is a neutral star, or even a black hole (if the degenerate pressure of neutrons can not withhold the gravitational pressure) • Heavy elements generated in the core collapse are send into the interstellar space through the explosion ...
Talk - ECT
... - Many open questions even for stable nuclei, precision experiments needed, - also important to pursue with RIB experiments and interpretation * Reaction Theory ! Ab initio theory <-> cross sections ...
... - Many open questions even for stable nuclei, precision experiments needed, - also important to pursue with RIB experiments and interpretation * Reaction Theory ! Ab initio theory <-> cross sections ...
This link is in pdf format for ease of reading
... Carinae is only barely visible to the naked eye. The rapidly expanding shell of material ejected during the last century's outburst (named the "homunculus" or the "little man" in 1950 by the Italian astronomer Gaviola) was the target of pre- servicing mission Hubble Space Telescope observations take ...
... Carinae is only barely visible to the naked eye. The rapidly expanding shell of material ejected during the last century's outburst (named the "homunculus" or the "little man" in 1950 by the Italian astronomer Gaviola) was the target of pre- servicing mission Hubble Space Telescope observations take ...
Sample Final
... a) supernova explosions cause new stars to form, then they evolve and supernova causing further star formation, and so on. b) stars can form all by themselves without help from spiral density waves or supernovae. c) stars always produce planetary systems that can support life. d) stars produce their ...
... a) supernova explosions cause new stars to form, then they evolve and supernova causing further star formation, and so on. b) stars can form all by themselves without help from spiral density waves or supernovae. c) stars always produce planetary systems that can support life. d) stars produce their ...
Stardust--Snapshots of Stars
... technique on the NanoSIMS that expands on automated methods developed in the early 2000s to study presolar grains . Preserved in primitive meteorites, presolar grains are literally stardust that formed in ancient stellar outflows and ejecta from supernova explosions, and became part of the molecular ...
... technique on the NanoSIMS that expands on automated methods developed in the early 2000s to study presolar grains . Preserved in primitive meteorites, presolar grains are literally stardust that formed in ancient stellar outflows and ejecta from supernova explosions, and became part of the molecular ...
Formation of the Universe
... The universe began about 14 billion years ago as an extremely hot, dense and compact state (singularity) that underwent an extremely violent expansion. ...
... The universe began about 14 billion years ago as an extremely hot, dense and compact state (singularity) that underwent an extremely violent expansion. ...
The first step towards getting somewhere is to decide you are not
... The first step towards getting somewhere is to decide you are not going to stay where you are. ...
... The first step towards getting somewhere is to decide you are not going to stay where you are. ...
Dr. Amanda Karakas and Prof. John Lattanzio
... Asymptotic Giant Branch stars • The asymptotic giant branch is the last nuclear burning phase for stars with mass < 8Msun • AGB stars are cool (~3000 K) evolved giants, spectral types M, S, C ...
... Asymptotic Giant Branch stars • The asymptotic giant branch is the last nuclear burning phase for stars with mass < 8Msun • AGB stars are cool (~3000 K) evolved giants, spectral types M, S, C ...
Document
... • 15-20 MeV for spherically-symmetrical collapse • 30-40 MeV for rotational-fission model is necessary to interpret the statistically significant signal from SN 1987A registered by the LSD neutrino detector Characteristic duration of the peak < 0.5 s About of 10% of total E is radiated in the peak ...
... • 15-20 MeV for spherically-symmetrical collapse • 30-40 MeV for rotational-fission model is necessary to interpret the statistically significant signal from SN 1987A registered by the LSD neutrino detector Characteristic duration of the peak < 0.5 s About of 10% of total E is radiated in the peak ...
Open clusters
... Some special stars change their luminosity with a regular pattern. For example, Cepheid Variable stars have a relationship between their luminosity and the period of variation. this can be used to determine the distance to the star. ...
... Some special stars change their luminosity with a regular pattern. For example, Cepheid Variable stars have a relationship between their luminosity and the period of variation. this can be used to determine the distance to the star. ...
Transcript of this week`s podcast
... after the Big Bang. For the effects of what happened from this time can still be observed today. From 10-35 of a second after its creation, the universe entered a phase that scientists since the early 1980s have called the inflationary epoch. During this inflationary epoch, the universe began expand ...
... after the Big Bang. For the effects of what happened from this time can still be observed today. From 10-35 of a second after its creation, the universe entered a phase that scientists since the early 1980s have called the inflationary epoch. During this inflationary epoch, the universe began expand ...
Astrophysics and Chemistry Review Guide
... Why do stars come in different colors? What is the brightest star (apparent) in the night sky as seen from Earth? What is the difference between apparent magnitude and absolute magnitude? What are 5 ways mass influences a star? About how far away is the sun? What is the chorus to the sun song? “The ...
... Why do stars come in different colors? What is the brightest star (apparent) in the night sky as seen from Earth? What is the difference between apparent magnitude and absolute magnitude? What are 5 ways mass influences a star? About how far away is the sun? What is the chorus to the sun song? “The ...
The Star–Gas–Star Cycle
... • fraction of heavy elements same as or greater than the Sun • plenty of high- and low-mass stars, blue and red ...
... • fraction of heavy elements same as or greater than the Sun • plenty of high- and low-mass stars, blue and red ...
PHYSICS 015
... During the main-sequence phases, the body of every star contains myriads of free electrons, torn off the fully ionized nuclei thanks to the extreme heat. They play no role in the energy generation and are just ‘part of the background.’ But as the core shrinks, everything is squashed more densely tog ...
... During the main-sequence phases, the body of every star contains myriads of free electrons, torn off the fully ionized nuclei thanks to the extreme heat. They play no role in the energy generation and are just ‘part of the background.’ But as the core shrinks, everything is squashed more densely tog ...
word document - FacStaff Home Page for CBU
... b) Big Bang (1) open and infinite (2) closed and finite Study Questions for Part C: *1. What are the three main cosmological facts? 2. Describe the steady state theory and discuss how it explains (or fails to explain) the three main cosmological facts. **3. Describe the "Big Bang" theory and discuss ...
... b) Big Bang (1) open and infinite (2) closed and finite Study Questions for Part C: *1. What are the three main cosmological facts? 2. Describe the steady state theory and discuss how it explains (or fails to explain) the three main cosmological facts. **3. Describe the "Big Bang" theory and discuss ...
Lecture13 - University of Waterloo
... • This reaction requires the neutrino to have an energy of 0.814 MeV or more, and can only detect neutrinos from the “side-reactions” in the PP chain: ...
... • This reaction requires the neutrino to have an energy of 0.814 MeV or more, and can only detect neutrinos from the “side-reactions” in the PP chain: ...
Looking for the siblings of the Sun
... in the early history of the solar system (Malhotra 2008) -Well-organized planetary system: the parental cluster cannot be very dense. -Presence of radioactive-isotopes in primitive meteorites, the Sun was polluted by a SN of star about 15-25 solar masses within a distance of 0.02-1.6 pc (Looney et a ...
... in the early history of the solar system (Malhotra 2008) -Well-organized planetary system: the parental cluster cannot be very dense. -Presence of radioactive-isotopes in primitive meteorites, the Sun was polluted by a SN of star about 15-25 solar masses within a distance of 0.02-1.6 pc (Looney et a ...
2. The Universe Is Expanding and Evolving
... Robert Dicke and his colleagues were using a small radiotelescope to search specifically for the CMB. When Penzias was eventually informed about Dicke’s work, he phoned him immediately in puzzlement about his results, and after the phone call Dicke said to his team “Boys, we’ve been scooped!” Penzia ...
... Robert Dicke and his colleagues were using a small radiotelescope to search specifically for the CMB. When Penzias was eventually informed about Dicke’s work, he phoned him immediately in puzzlement about his results, and after the phone call Dicke said to his team “Boys, we’ve been scooped!” Penzia ...
Document
... Water is constantly eroding salts out of rocks. This is carried by rivers into the oceans. More enters than leaves so there is a gradual build up of the concentration. By measuring the amount entering & the present salinity, an upper age limit can be calculated. If the oceans were salty at formation ...
... Water is constantly eroding salts out of rocks. This is carried by rivers into the oceans. More enters than leaves so there is a gradual build up of the concentration. By measuring the amount entering & the present salinity, an upper age limit can be calculated. If the oceans were salty at formation ...
Topic 7_2_Ext B__Nuclear stability
... Question: If the universe started7.2 out asExtended hydrogen and helium, and Topic stars can only breed nuclei up to iron, where do all the higher elements B – Nuclear Stability come from? BINDING ENERGY This brings us to an aside on stellar evolution: During the lifetime of a star there are two o ...
... Question: If the universe started7.2 out asExtended hydrogen and helium, and Topic stars can only breed nuclei up to iron, where do all the higher elements B – Nuclear Stability come from? BINDING ENERGY This brings us to an aside on stellar evolution: During the lifetime of a star there are two o ...
White dwarfs - University of Toronto
... A Type Ia supernova more than twice as bright as others of its type has been observed, suggesting it arose from a star that managed to grow more massive than the Chandrasekhar limit. This mass cut-off was thought to make all such supernovae explode with about the same intrinsic brightness, allowing ...
... A Type Ia supernova more than twice as bright as others of its type has been observed, suggesting it arose from a star that managed to grow more massive than the Chandrasekhar limit. This mass cut-off was thought to make all such supernovae explode with about the same intrinsic brightness, allowing ...
Goal: To understand the lifetime of a star and how the
... • No, we don’t get a Helium atom with 2 protons and no neutrons. Those don’t exist. • Another difficulty in the fusion process is that you turn 2 protons into deuterium (which is hydrogen with a neutron in it) + stuff. • So, that means a proton has to convert to a neutron. That is hard to do. ...
... • No, we don’t get a Helium atom with 2 protons and no neutrons. Those don’t exist. • Another difficulty in the fusion process is that you turn 2 protons into deuterium (which is hydrogen with a neutron in it) + stuff. • So, that means a proton has to convert to a neutron. That is hard to do. ...
Stellar Evolution: The Live and Death of a Star
... It continues to spread out over time, and eventually disperses into interstellar space, enriching it with atoms of helium, carbon, oxygen & heavier elements • These elements eventually get swept up into nebulae (see ch. 18) and formed into new stars and planets ...
... It continues to spread out over time, and eventually disperses into interstellar space, enriching it with atoms of helium, carbon, oxygen & heavier elements • These elements eventually get swept up into nebulae (see ch. 18) and formed into new stars and planets ...
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.