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... The strength of the Lithium line can be calibrated with age, but it is generally not that good. In a solar type star the presence of Lithium most likely means it is young. But the processes that affect the strength of lithium are poorly known. For instance, strong Li is also found in some evolved gi ...
... The strength of the Lithium line can be calibrated with age, but it is generally not that good. In a solar type star the presence of Lithium most likely means it is young. But the processes that affect the strength of lithium are poorly known. For instance, strong Li is also found in some evolved gi ...
Pulsars
... • Rotation and magnetic polar axes shown co-aligned • Induced E field removes charge from the surface so charge and currents must exist above the surface – the Magnetosphere • Light cylinder is at the radial distance at which rotational velocity of co-rotating particles equals velocity of light • Op ...
... • Rotation and magnetic polar axes shown co-aligned • Induced E field removes charge from the surface so charge and currents must exist above the surface – the Magnetosphere • Light cylinder is at the radial distance at which rotational velocity of co-rotating particles equals velocity of light • Op ...
Eruptive Variables - Scientific Research Publishing
... the density nor the coefficient of opacity [3]. The stars differ in brightness, density and other conditions, but they mostly contain about the same amount of material. The majority are between 1033 gm and 1034 gm. where the serious challenge of radiation pressure to compete with hot gases pressure ...
... the density nor the coefficient of opacity [3]. The stars differ in brightness, density and other conditions, but they mostly contain about the same amount of material. The majority are between 1033 gm and 1034 gm. where the serious challenge of radiation pressure to compete with hot gases pressure ...
Stellar Winds and Supernova Remnants: Interaction with the ISM
... IRC+10216 showing shell-like structures in the circumstellar envelope (90''x 90'') Mauron & Huggins (2010) ...
... IRC+10216 showing shell-like structures in the circumstellar envelope (90''x 90'') Mauron & Huggins (2010) ...
Early Universe and Thermal History
... During the early stages the temperature went through a large range or values (many orders of magnitude). From conventional solid state physics we know that temperature changes can produce phase transitions, and there are commonly known examples of that: ferro-magnets, water drops condensing out of f ...
... During the early stages the temperature went through a large range or values (many orders of magnitude). From conventional solid state physics we know that temperature changes can produce phase transitions, and there are commonly known examples of that: ferro-magnets, water drops condensing out of f ...
Deep HST Imaging of M33: Reliability and Recovery of the Star
... • Stellar atmosperes tell us how effective temperature, composition, and surface gravity (from mass and luminosity) are related to spectrum/colors • Results embodied in stellar isochrones ...
... • Stellar atmosperes tell us how effective temperature, composition, and surface gravity (from mass and luminosity) are related to spectrum/colors • Results embodied in stellar isochrones ...
Power point
... due to shell effects, magic numbers • Symmetric fission is suppressed by at least two orders of magnitude relative to asymmetric fission ...
... due to shell effects, magic numbers • Symmetric fission is suppressed by at least two orders of magnitude relative to asymmetric fission ...
Accuracy of spectroscopy-based radioactive dating of stars
... r-process it is not obvious that the outcome is the same for a potentially wide range of the physical conditions governing the formation site(s) (Goriely & Clerbaux 1999; Arnould et al. 2007; Sneden et al. 2008; Roederer et al. 2009). To minimize the influence of poorly constrained physical conditio ...
... r-process it is not obvious that the outcome is the same for a potentially wide range of the physical conditions governing the formation site(s) (Goriely & Clerbaux 1999; Arnould et al. 2007; Sneden et al. 2008; Roederer et al. 2009). To minimize the influence of poorly constrained physical conditio ...
The Abundances of the Fe Group Elements in Three Early B Stars in
... spectrum of early B stars. We have completed our analysis of AV 304 in the SMC and are currently pursuing an NLTE study of four other sharp-lined early B stars in the Magellanic Clouds as the first step toward mapping the abundances of the Fe group elements in these galaxies from photospheric data. ...
... spectrum of early B stars. We have completed our analysis of AV 304 in the SMC and are currently pursuing an NLTE study of four other sharp-lined early B stars in the Magellanic Clouds as the first step toward mapping the abundances of the Fe group elements in these galaxies from photospheric data. ...
The Universe - The Ohio State University
... reason that He+ was the first atomic species was due to the extremely hot plasma when nuclei and electrons were free in fully ionized state. The atomic species that would form first is the one with the highest ionization potential (EIP ). EIP for (He+ ) = Z 2 = 4 Ryd = 54 eV, as opposed to EIP (He) ...
... reason that He+ was the first atomic species was due to the extremely hot plasma when nuclei and electrons were free in fully ionized state. The atomic species that would form first is the one with the highest ionization potential (EIP ). EIP for (He+ ) = Z 2 = 4 Ryd = 54 eV, as opposed to EIP (He) ...
Slide 1
... Calculate the ages of the coolest white dwarf stars: White dwarf cosmochronology • Critical theoretical uncertainties for dating the coolest WDs – Outer layers • Convection, degeneracy, and radiative opacity ...
... Calculate the ages of the coolest white dwarf stars: White dwarf cosmochronology • Critical theoretical uncertainties for dating the coolest WDs – Outer layers • Convection, degeneracy, and radiative opacity ...
Vasiliki Pavlidou - Center for Particle and Gravitational Astrophysics
... nearby transient (merger between compact objects ?) GLAST detects it as a very bright transient gamma-ray source. Follow up with Cherenkov detectors - high angular resolution. LIGO detects gravitational wave emission; nature of progenitor known at high confidence A success story Low-energy m ...
... nearby transient (merger between compact objects ?) GLAST detects it as a very bright transient gamma-ray source. Follow up with Cherenkov detectors - high angular resolution. LIGO detects gravitational wave emission; nature of progenitor known at high confidence A success story Low-energy m ...
Slide 1
... - but not representative for composition of entire Earth Earth is also not representative for solar system composition Chemical and physical fractionations during (1) formation of planetesimals from molecular cloud material processed in the protoplanetary accretion disk (solar nebula) (2) differenti ...
... - but not representative for composition of entire Earth Earth is also not representative for solar system composition Chemical and physical fractionations during (1) formation of planetesimals from molecular cloud material processed in the protoplanetary accretion disk (solar nebula) (2) differenti ...
The Magnetic Field Profile in Strongly Magnetized Neutron Stars
... a massive star ad hoc ad hoc ...
... a massive star ad hoc ad hoc ...
Lecture 9
... Stellar Evolution As the helium core grows, it compresses. Helium doesn’t fuse to heavier elements for two reasons. (1) with 2 p+ per nucleus, the electric repulsion force is higher than was the case for H-fusion. This means that helium fusion requires a higher temperature than hydrogen fusion ...
... Stellar Evolution As the helium core grows, it compresses. Helium doesn’t fuse to heavier elements for two reasons. (1) with 2 p+ per nucleus, the electric repulsion force is higher than was the case for H-fusion. This means that helium fusion requires a higher temperature than hydrogen fusion ...
Supercritical clouds
... • No way of initiating collapse if supporting magnetic flux is frozen-in. • Solution: only (molecular) ions are tied to field lines. • Ambipolar diffusion: field lines can slip through the neutrals, allowing supercritical cores to form. • Long diffusion timescale means inefficient star formation. ...
... • No way of initiating collapse if supporting magnetic flux is frozen-in. • Solution: only (molecular) ions are tied to field lines. • Ambipolar diffusion: field lines can slip through the neutrals, allowing supercritical cores to form. • Long diffusion timescale means inefficient star formation. ...
Chapter 10 Nuclear Properties
... individual electrons into different quantum “orbitals”, with orbitals being filled according to energy hierarchy, with a maximum of two electrons (spin up and spin down) to an orbital. Nucleons are formed in much the same way, except that all the force is provided by the other constituent nucleons, ...
... individual electrons into different quantum “orbitals”, with orbitals being filled according to energy hierarchy, with a maximum of two electrons (spin up and spin down) to an orbital. Nucleons are formed in much the same way, except that all the force is provided by the other constituent nucleons, ...
Lecture 2 - SUNY Oswego
... This layer heats up and becomes more opaque to radiation. Radiation diffuses more slowly through the layer because of its increased opacity and heat builds up beneath it. Pressure rises below the layer and eventually starts to push the layer out. The layer expands, cools and becomes more transparent ...
... This layer heats up and becomes more opaque to radiation. Radiation diffuses more slowly through the layer because of its increased opacity and heat builds up beneath it. Pressure rises below the layer and eventually starts to push the layer out. The layer expands, cools and becomes more transparent ...
Lives of Stars - Amazon Web Services
... material from the star is left behind. This material may form a neutron star. Neutron stars are the remains of high-mass stars. They are even smaller and denser than white dwarfs. A neutron star may contain as much as three times the mass of the sun but be only about 25 kilometers in diameter, the s ...
... material from the star is left behind. This material may form a neutron star. Neutron stars are the remains of high-mass stars. They are even smaller and denser than white dwarfs. A neutron star may contain as much as three times the mass of the sun but be only about 25 kilometers in diameter, the s ...
Future Supernova Projects
... • small dispersion • single objects (simpler than galaxies) • can be observed over wide z range Challenges: • dust (grey dust) • chemical composition • evolution • photometric calibration (e.g., Vega) • environmental differences Systematics • lensing Step 2 ...
... • small dispersion • single objects (simpler than galaxies) • can be observed over wide z range Challenges: • dust (grey dust) • chemical composition • evolution • photometric calibration (e.g., Vega) • environmental differences Systematics • lensing Step 2 ...
P-nuclei
p-Nuclei (p stands for proton-rich) are certain proton-rich, naturally occurring isotopes of some elements between selenium and mercury which cannot be produced in either s- or r-process.