ASTR 1020 General Astronomy: Stars and Galaxies REVIEW
... Regular stars need thermal pressure to balance gravity, and they need nuclear reactions to maintain the pressure, so the die when they run out of fuel. Not so White Dwarfs. They are as stable as a rock. Literally. A quadrillion years in the future all the stars will be gone, but the White Dwarfs wil ...
... Regular stars need thermal pressure to balance gravity, and they need nuclear reactions to maintain the pressure, so the die when they run out of fuel. Not so White Dwarfs. They are as stable as a rock. Literally. A quadrillion years in the future all the stars will be gone, but the White Dwarfs wil ...
giant molecular clouds
... Large masses of Giant Molecular Clouds => Stars do not form isolated, but in large groups, called Open Clusters of Stars. ...
... Large masses of Giant Molecular Clouds => Stars do not form isolated, but in large groups, called Open Clusters of Stars. ...
http://www.highpoint.edu/~afuller/PHY-1050
... End of Fusion • Fusion progresses no further in a low-mass star because the core temperature never grows hot enough for fusion of heavier elements (some helium fuses to carbon to make oxygen). • All that remains is the exposed core of the star, called a white dwarf. • Degeneracy pressure supports t ...
... End of Fusion • Fusion progresses no further in a low-mass star because the core temperature never grows hot enough for fusion of heavier elements (some helium fuses to carbon to make oxygen). • All that remains is the exposed core of the star, called a white dwarf. • Degeneracy pressure supports t ...
Precision Nuclear Mass Measurements
... What is the mass of an atom with Z protons and electrons and N neutrons? protons ...
... What is the mass of an atom with Z protons and electrons and N neutrons? protons ...
Dynamics of neutrino-driven winds: inclusion of accurate weak
... when the MF is lower than 1015 G, such as 1013 and 1014 G, no significant differences are found. Actually because the curves for such low MFs nearly coincide with those without an MF, they are not shown in Figure 1. In addition, as the temperature near the PNS is very high (more than 1010 K), the ch ...
... when the MF is lower than 1015 G, such as 1013 and 1014 G, no significant differences are found. Actually because the curves for such low MFs nearly coincide with those without an MF, they are not shown in Figure 1. In addition, as the temperature near the PNS is very high (more than 1010 K), the ch ...
Sec 29.3 - Highland High School
... Internal pressure in white dwarfs A white dwarf is stable despite its lack of nuclear reactions because it is supported by the resistance of electrons being squeezed together. This pressure counteracts gravity and can support the core as long as the mass of the remaining core is less than about 1.4 ...
... Internal pressure in white dwarfs A white dwarf is stable despite its lack of nuclear reactions because it is supported by the resistance of electrons being squeezed together. This pressure counteracts gravity and can support the core as long as the mass of the remaining core is less than about 1.4 ...
Cardassian Expansion - University of Michigan
... and rely on for our existence could not exist without stars. ...
... and rely on for our existence could not exist without stars. ...
Spectroscopy PPT
... The dark lines are in the exact same place as the bright lines would be for the same element in a bright-line spectrum. ...
... The dark lines are in the exact same place as the bright lines would be for the same element in a bright-line spectrum. ...
HR Diagrams
... this by plotting the students in your class on a graph, with height on one axis and weight on the other. Each student would be plotted as a point on the graph. What do you think that graph would look like? In general, shorter people tend to weigh less and taller people tend to weigh more. So, your g ...
... this by plotting the students in your class on a graph, with height on one axis and weight on the other. Each student would be plotted as a point on the graph. What do you think that graph would look like? In general, shorter people tend to weigh less and taller people tend to weigh more. So, your g ...
f) Organizing the Elements Metals Nonmetals and
... Mendeleev's Work Mendeleev knew that some elements have similar chemical and physical properties. For example, both fluorine and chlorine are gases that irritate the lungs and form similar compounds. Silver and copper, shown in Figure 5, are both shiny metals that tarnish if exposed to air. Mendelee ...
... Mendeleev's Work Mendeleev knew that some elements have similar chemical and physical properties. For example, both fluorine and chlorine are gases that irritate the lungs and form similar compounds. Silver and copper, shown in Figure 5, are both shiny metals that tarnish if exposed to air. Mendelee ...
Rotational spin-up in the 30-Myr
... one of the fundamental quantities, like mass and metallicity, defining the star’s properties and evolution. Rotation influences the star’s internal structure and the mixing processes in the stellar interior that are reflected in surface elemental abundances. It is also the main driver for magnetic a ...
... one of the fundamental quantities, like mass and metallicity, defining the star’s properties and evolution. Rotation influences the star’s internal structure and the mixing processes in the stellar interior that are reflected in surface elemental abundances. It is also the main driver for magnetic a ...
Chapter 12: The Life Cycle of Stars (contʼd)
... • the period of a massive star's life when carbon, nitrogen, and oxygen are fusing in different shells outside the core • a type of hydrogen fusion that uses carbon, nitrogen, and oxygen atoms as catalysts • the process by which helium is fused into carbon, nitrogen, and oxygen • the perio ...
... • the period of a massive star's life when carbon, nitrogen, and oxygen are fusing in different shells outside the core • a type of hydrogen fusion that uses carbon, nitrogen, and oxygen atoms as catalysts • the process by which helium is fused into carbon, nitrogen, and oxygen • the perio ...
The Universe - Cloudfront.net
... Concept Check What relationship did Hubble discover between red shifts and the distances of galaxies from Earth? Galaxies that have the greatest red shifts are the most distant. ...
... Concept Check What relationship did Hubble discover between red shifts and the distances of galaxies from Earth? Galaxies that have the greatest red shifts are the most distant. ...
31 October: Supernovae and Neutron Stars
... Formation of a neutron star from stellar core • As core collapses, matter becomes compressed • Electrons and protons forced together e+p > n + nu (neutronization) • Core of the becomes a neutron fluid • Neutronization produces a burst of neutrinos • Neutron fluid in core becomes degenerate and rigi ...
... Formation of a neutron star from stellar core • As core collapses, matter becomes compressed • Electrons and protons forced together e+p > n + nu (neutronization) • Core of the becomes a neutron fluid • Neutronization produces a burst of neutrinos • Neutron fluid in core becomes degenerate and rigi ...
protostars and pre-main-sequence evolution.key
... using guessed central values for P, T, iterate until match with outer boundary conditions. ...
... using guessed central values for P, T, iterate until match with outer boundary conditions. ...
Reprint
... The origin of carbon lies in nucleosynthesis in stars. There are two main contributors to carbon, supernovae (12 C) and evolved stars (12 C and 13 C), including red giants, supergiants, and asymptotic giant branch (AGB) stars. Stellar yields from such objects result in an average galactic C/O ratio ...
... The origin of carbon lies in nucleosynthesis in stars. There are two main contributors to carbon, supernovae (12 C) and evolved stars (12 C and 13 C), including red giants, supergiants, and asymptotic giant branch (AGB) stars. Stellar yields from such objects result in an average galactic C/O ratio ...
Supernovae
... rebound in which the outer parts of the star are blown away The visible/X-ray supernova results due to radiation from this exploded material and later from shock-heated interstellar ...
... rebound in which the outer parts of the star are blown away The visible/X-ray supernova results due to radiation from this exploded material and later from shock-heated interstellar ...
isotopes, relative atomic mass and mass
... Atoms within an element that have the same number of protons and electrons but a different number of neutrons are called ISOTOPES of that element. Isotopes of an element are chemically identical because it is the number of protons and electrons, rather than the number of neutrons, which determines t ...
... Atoms within an element that have the same number of protons and electrons but a different number of neutrons are called ISOTOPES of that element. Isotopes of an element are chemically identical because it is the number of protons and electrons, rather than the number of neutrons, which determines t ...
PowerPoint
... intensity left over after a given time to that predicted by the half life of the isotope. • Positron emitters can be used for PET scanning of isotope distribution inside a human/animal body. ...
... intensity left over after a given time to that predicted by the half life of the isotope. • Positron emitters can be used for PET scanning of isotope distribution inside a human/animal body. ...
Life Cycle of Stars
... temperature of a star determines its color – from cool, red stars to hot, blue ones. The Sun is a medium temperature yellow star. Around 1910, astronomers Ejnar Hertzsprung and Henry Russell independently developed what is now known as the Hertzsprung-Russell or H-R diagram. This graph plots the rel ...
... temperature of a star determines its color – from cool, red stars to hot, blue ones. The Sun is a medium temperature yellow star. Around 1910, astronomers Ejnar Hertzsprung and Henry Russell independently developed what is now known as the Hertzsprung-Russell or H-R diagram. This graph plots the rel ...
Lecture - Ann Arbor Earth Science
... calculate it based on other observations. It can be determined either by the inertial properties of the body or by its gravitational influence on other bodies. The larger the mass, the stronger the gravitational effect on the bodies around it. Stellar masses are expressed as multiples of the mass of ...
... calculate it based on other observations. It can be determined either by the inertial properties of the body or by its gravitational influence on other bodies. The larger the mass, the stronger the gravitational effect on the bodies around it. Stellar masses are expressed as multiples of the mass of ...
Document
... calculate it based on other observations. It can be determined either by the inertial properties of the body or by its gravitational influence on other bodies. The larger the mass, the stronger the gravitational effect on the bodies around it. Stellar masses are expressed as multiples of the mass of ...
... calculate it based on other observations. It can be determined either by the inertial properties of the body or by its gravitational influence on other bodies. The larger the mass, the stronger the gravitational effect on the bodies around it. Stellar masses are expressed as multiples of the mass of ...
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.