Fermi Gases
... • But also have filled energy levels and need to give enough energy to p/n so that there is an unfilled state available. Simplest to say “above” Fermi Energy • similar effect in solids. Superconductivity mostly involves electrons at the “top” of the Fermi well ...
... • But also have filled energy levels and need to give enough energy to p/n so that there is an unfilled state available. Simplest to say “above” Fermi Energy • similar effect in solids. Superconductivity mostly involves electrons at the “top” of the Fermi well ...
Variable Stars as Essential Astrophysical Tools
... We search for correlation in the signal using a modified f-test. Define : f = variance of full data set/variance of consecutive night differences 81 times we have data on a night when we had data the previous night ...
... We search for correlation in the signal using a modified f-test. Define : f = variance of full data set/variance of consecutive night differences 81 times we have data on a night when we had data the previous night ...
Sample Test 22
... 20 times that of the Sun. The star ejected the material about 20,000 years ago, leaving a star with a hotter, bluer surface. 3. An increase in neutrinos was observed some three hours before the supernova was seen, confirming an important part of the theory of supernovae. 4. Supernovae events are sin ...
... 20 times that of the Sun. The star ejected the material about 20,000 years ago, leaving a star with a hotter, bluer surface. 3. An increase in neutrinos was observed some three hours before the supernova was seen, confirming an important part of the theory of supernovae. 4. Supernovae events are sin ...
Compact Extragalactic Star Formation
... massive star clusters? How do they evolve to become globular clusters today? What is the luminosity function of SSCs, and the mass function of their star formation? • Is optical/IR modeling of star formation in SSCs consistent with radio observations? • How do supernovae evolve in dense environments ...
... massive star clusters? How do they evolve to become globular clusters today? What is the luminosity function of SSCs, and the mass function of their star formation? • Is optical/IR modeling of star formation in SSCs consistent with radio observations? • How do supernovae evolve in dense environments ...
Stellar Evolution
... • “The hourglass shapes of many planetary nebulae are produced by the expansion of a ‘fast stellar wind’ within a slowly expanding ’cloud’ which is denser near its equator than its poles.” • If so, where do the x-rays come from? ...
... • “The hourglass shapes of many planetary nebulae are produced by the expansion of a ‘fast stellar wind’ within a slowly expanding ’cloud’ which is denser near its equator than its poles.” • If so, where do the x-rays come from? ...
Nuclear Reactions
... which is a function of vAB . We must view the reaction in the center of mass frame, and the kinetic energy E is the energy of A + B measured in that frame, the relative velocity vAB is measured in that frame as well, but is the same as in the frame in which one of the 2 nuclei is at rest, and is 2E/ ...
... which is a function of vAB . We must view the reaction in the center of mass frame, and the kinetic energy E is the energy of A + B measured in that frame, the relative velocity vAB is measured in that frame as well, but is the same as in the frame in which one of the 2 nuclei is at rest, and is 2E/ ...
main-sequence stars
... more luminous and have diameters from 10-100 times greater than our sun. Super giants are giant stars that have diameters more than 100 times greater than our sun. These giant stars (but relatively cool) are very luminous. ...
... more luminous and have diameters from 10-100 times greater than our sun. Super giants are giant stars that have diameters more than 100 times greater than our sun. These giant stars (but relatively cool) are very luminous. ...
M - IMAG2E
... Students will learn how to interpret observational characteristics of stars in terms of the underlying physical parameters ...
... Students will learn how to interpret observational characteristics of stars in terms of the underlying physical parameters ...
1. What is the HR diagram? 1a. The HR diagram is a plot of a star`s
... The explosive start to Helium burning in the core for low mass stars. On the horizontal branch, how is the star powered? What burns where? Helium burning in the core. No real shell burning at this stage. On the asymptotic giant branch (AGB), can you ever get a helium burning shell outside a hydrogen ...
... The explosive start to Helium burning in the core for low mass stars. On the horizontal branch, how is the star powered? What burns where? Helium burning in the core. No real shell burning at this stage. On the asymptotic giant branch (AGB), can you ever get a helium burning shell outside a hydrogen ...
Lecture Notes – Stars
... gradually cools off and becomes a brown dwarf. Main Sequence Evolution Stars on main sequence convert H to He via PP chain or CNO cycle. A G2V star like Sun will be initially composed of 73% hydrogen, 25% helium and 2% other elements. The duration of main sequence (τms ) phase depends on the amount ...
... gradually cools off and becomes a brown dwarf. Main Sequence Evolution Stars on main sequence convert H to He via PP chain or CNO cycle. A G2V star like Sun will be initially composed of 73% hydrogen, 25% helium and 2% other elements. The duration of main sequence (τms ) phase depends on the amount ...
Recipe for a Star
... supernova. The explosion is so powerful that it can briefly outshine an entire galaxy. It is the most violent and spectacular explosion in the universe. While the core explosion occurs in about one second, the massive-star supernova may continue to shine for weeks or months. Massive-star supernovae ...
... supernova. The explosion is so powerful that it can briefly outshine an entire galaxy. It is the most violent and spectacular explosion in the universe. While the core explosion occurs in about one second, the massive-star supernova may continue to shine for weeks or months. Massive-star supernovae ...
How physicists study the structure of matter
... to the airport and asking the security guards there to use their X-ray machine to examine your gift. That’s a good idea. However, all you find out is that there is a smaller box inside, made of thick plates of lead. You still cannot see what’s inside the smaller box even with the X-rays. So, what sh ...
... to the airport and asking the security guards there to use their X-ray machine to examine your gift. That’s a good idea. However, all you find out is that there is a smaller box inside, made of thick plates of lead. You still cannot see what’s inside the smaller box even with the X-rays. So, what sh ...
Lecture 1
... 1951: Detection of 21cm line by Ewen & Purcell using home-build radio detector. Beat Oort & Muller to it. HI is seen everywhere in the sky. 1954: First maps of the HI distribution in the Milky Way by Hulst, Muller & Oort. The Galactic disk is estimated to contain 5ₒ109M⊙ of atomic gas (ca. 10% of th ...
... 1951: Detection of 21cm line by Ewen & Purcell using home-build radio detector. Beat Oort & Muller to it. HI is seen everywhere in the sky. 1954: First maps of the HI distribution in the Milky Way by Hulst, Muller & Oort. The Galactic disk is estimated to contain 5ₒ109M⊙ of atomic gas (ca. 10% of th ...
Star Formation
... Stars not yet on the main sequence – find a cluster in which the massive stars are already on the main sequence, but the low-mass stars are not yet there. This is because their gravity is weaker, and they collapse somewhat more slowly as they form! T Tauri stars – young stars, including some called ...
... Stars not yet on the main sequence – find a cluster in which the massive stars are already on the main sequence, but the low-mass stars are not yet there. This is because their gravity is weaker, and they collapse somewhat more slowly as they form! T Tauri stars – young stars, including some called ...
File
... To show that light is broken into many colors. Red light has a longer, more stretched-out wavelength. Galaxies that are moving away from us appear red. This shows that the universe is expanding, which supports the Big Bang theory. ...
... To show that light is broken into many colors. Red light has a longer, more stretched-out wavelength. Galaxies that are moving away from us appear red. This shows that the universe is expanding, which supports the Big Bang theory. ...
New Theory of Nuclear Fusion Processes in Sun and other
... The heat produced in these fusion reactions will be absorbed by the plasma almost evenly across the sun due to extreme turbulence (Magneto hydrodynamics MHD – causing stirring of plasma) inside its core and will keep it stable by supplying this energy to plasma causing its appearance to be of unifor ...
... The heat produced in these fusion reactions will be absorbed by the plasma almost evenly across the sun due to extreme turbulence (Magneto hydrodynamics MHD – causing stirring of plasma) inside its core and will keep it stable by supplying this energy to plasma causing its appearance to be of unifor ...
FINAL STAGES OF MASSIVE STARS. SN EXPLOSION AND
... Production of long-lived radioactive isotopes: (26Al, 56Co, 57Co, 44Ti, 60Fe) GRB progenitors The understanding of these stars, is crucial for the interpretation of many astrophysical evidences ...
... Production of long-lived radioactive isotopes: (26Al, 56Co, 57Co, 44Ti, 60Fe) GRB progenitors The understanding of these stars, is crucial for the interpretation of many astrophysical evidences ...
BIG BANG –Webquest
... GO to the following site: http://www.windows2universe.org/the_universe/AllStarTop.html a. Click “The Sun.” How much time does light take to travel from the sun to Earth? ____________________ b. Hit the back button. Click “Sirius A” (the BRIGHTEST star in the sky!) How much time does light take to tr ...
... GO to the following site: http://www.windows2universe.org/the_universe/AllStarTop.html a. Click “The Sun.” How much time does light take to travel from the sun to Earth? ____________________ b. Hit the back button. Click “Sirius A” (the BRIGHTEST star in the sky!) How much time does light take to tr ...
Slide 1
... The hydrogen found in water and hydrocarbons was formed in the moments after the Big Bang. Carbon, the basis for all terrestrial life, was formed in small stars. Elements of lower abundance in living organisms but essential to our biology, such as calcium and iron, were formed in large stars. Heavie ...
... The hydrogen found in water and hydrocarbons was formed in the moments after the Big Bang. Carbon, the basis for all terrestrial life, was formed in small stars. Elements of lower abundance in living organisms but essential to our biology, such as calcium and iron, were formed in large stars. Heavie ...
ps700-coll1-hayden
... having a well paced structure helped the sometimes seemingly complex ideas (For nonscientists) appear simpler. I was impressed with the relevance of a lot of the images used, helping the ideas laid out in words be reinforced by visual means, this was especially true with the diagram of the galaxy in ...
... having a well paced structure helped the sometimes seemingly complex ideas (For nonscientists) appear simpler. I was impressed with the relevance of a lot of the images used, helping the ideas laid out in words be reinforced by visual means, this was especially true with the diagram of the galaxy in ...
Document
... The problem of damping of stellar oscillations in presence of a Urca shell is solved analytically in a plane symmetrical approximation. Low-amplitude oscillations are considered. Oscillatory pressure perturbations induce beta reactions of the electron capture and decay in the thin layer around the U ...
... The problem of damping of stellar oscillations in presence of a Urca shell is solved analytically in a plane symmetrical approximation. Low-amplitude oscillations are considered. Oscillatory pressure perturbations induce beta reactions of the electron capture and decay in the thin layer around the U ...
1 solar and stellar abundances of the elements
... regions becomes converted into helium until eventually all the energy is generated in a thin shell surrounding an inert contracting core. Then the outer portion of the star becomes distended, the radius of the star increases and its surface temperature falls. Eventually, as the core of the star cont ...
... regions becomes converted into helium until eventually all the energy is generated in a thin shell surrounding an inert contracting core. Then the outer portion of the star becomes distended, the radius of the star increases and its surface temperature falls. Eventually, as the core of the star cont ...
Class notes 2 - University of Texas Astronomy
... Nearest star (at ~ 1.3 pc): Proxima Centauri, currently the nearest member of the triple system α Centauri. Other stars: ⎯ well spaced out; interstellar space is very empty. Mean distance between stars ~ 1 pc ~ 4 × 107 their radius (⇒ don't collide within lifetime of Galaxy, ~ 1010 years); ⎯ major ...
... Nearest star (at ~ 1.3 pc): Proxima Centauri, currently the nearest member of the triple system α Centauri. Other stars: ⎯ well spaced out; interstellar space is very empty. Mean distance between stars ~ 1 pc ~ 4 × 107 their radius (⇒ don't collide within lifetime of Galaxy, ~ 1010 years); ⎯ major ...
dark matter
... Chemical evolution Finished last time by saying that all elements heavier than hydrogen and helium were formed in stars. The younger a star, the more material from previous generations of stars it will contain, and the higher their metallicity. Stars can be broadly split into two populations: Popula ...
... Chemical evolution Finished last time by saying that all elements heavier than hydrogen and helium were formed in stars. The younger a star, the more material from previous generations of stars it will contain, and the higher their metallicity. Stars can be broadly split into two populations: Popula ...
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... X-Ray Bursters and Millisecond Pulsars Neutron stars can be in accreting binaries ...
... X-Ray Bursters and Millisecond Pulsars Neutron stars can be in accreting binaries ...
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.