Chapter 6
... eject the mantle of the star (less than 1051 ergs). But as the shock wave travels through the outer iron core, it heats and melts the iron that crosses the shock front, at a loss of ∼ 8 MeV/nucleon, reversing the effects of all prior stages of quiescent stellar burning. The net drain of energy from ...
... eject the mantle of the star (less than 1051 ergs). But as the shock wave travels through the outer iron core, it heats and melts the iron that crosses the shock front, at a loss of ∼ 8 MeV/nucleon, reversing the effects of all prior stages of quiescent stellar burning. The net drain of energy from ...
The Spectra of Stars
... • Color of a star depends on its Temperature Color of a star depends on its Temperature – Red Stars are Cooler – Blue Stars are Hotter ...
... • Color of a star depends on its Temperature Color of a star depends on its Temperature – Red Stars are Cooler – Blue Stars are Hotter ...
B – V
... from Q (measured from UBV). Once (B – V)0 and (U – V)0 are known we find E(B – V) from (B – V). This only works for stars up to spectral type A0. Reason: The reddening happens to have the same slope as unreddened main sequence stars for late-type stars. Reddening free indices can also be defined for ...
... from Q (measured from UBV). Once (B – V)0 and (U – V)0 are known we find E(B – V) from (B – V). This only works for stars up to spectral type A0. Reason: The reddening happens to have the same slope as unreddened main sequence stars for late-type stars. Reddening free indices can also be defined for ...
A minimum column density of 1gcm(
... effective adiabatic index c < 1.4 throughout its volume. As even c < 1.1–1.2 is sufficient to suppress fragmentation5, equation (1) implicitly defines a critical light-to-mass ratio ghalt above which fragmentation will halt in a cloud with a given S, d and Tb. We describe our procedure for solving t ...
... effective adiabatic index c < 1.4 throughout its volume. As even c < 1.1–1.2 is sufficient to suppress fragmentation5, equation (1) implicitly defines a critical light-to-mass ratio ghalt above which fragmentation will halt in a cloud with a given S, d and Tb. We describe our procedure for solving t ...
AN INTERSTELLAR CLOUD WITH A HIGH CON
... size, nevertheless, that the suggested association of the CN molecules observed in the stars embedded in Shl 71 with the HI material surrounding the nebula has some antecedents. The Doppler shifts of the interstellar lines given in Table 1 provide some specific evidence in favor of the idea that the ...
... size, nevertheless, that the suggested association of the CN molecules observed in the stars embedded in Shl 71 with the HI material surrounding the nebula has some antecedents. The Doppler shifts of the interstellar lines given in Table 1 provide some specific evidence in favor of the idea that the ...
Gemini = برج الجوزاء (May 22
... Capricornus has as many mythological tales as it has stars. Capricornus gets its name from a Greek myth that says the god Pan was transformed into a half-goat, half-fish when he dived into the Nile River to escape the giant Typhon. • Capricornus looks like a large triangle of fairly bright stars. Th ...
... Capricornus has as many mythological tales as it has stars. Capricornus gets its name from a Greek myth that says the god Pan was transformed into a half-goat, half-fish when he dived into the Nile River to escape the giant Typhon. • Capricornus looks like a large triangle of fairly bright stars. Th ...
Evolution of low- and intermediate mass stars
... mesh points by considering only the region bereaches the point where our 3D calculation ...
... mesh points by considering only the region bereaches the point where our 3D calculation ...
Hot HB stars in globular clusters
... has been proven spectroscopically. While the helium abundance (one tenth solar) of F1-1 is typical for sdB stars, F2-2 surprisingly turned out to be a helium rich star, the first to be reported as a member of a globular cluster. In the field population of the Milky Way such stars are rare (less than ...
... has been proven spectroscopically. While the helium abundance (one tenth solar) of F1-1 is typical for sdB stars, F2-2 surprisingly turned out to be a helium rich star, the first to be reported as a member of a globular cluster. In the field population of the Milky Way such stars are rare (less than ...
Interstellar Astrophysics Summary notes: Part 5
... the position of their knots, brightness and shape over timescales of years, indicating the dynamical character of these bipolar outflows. In addition to these ejections the protostar can also gain some mass by the process of accretion. The main concepts here are: (i) as the protostar nebula contract ...
... the position of their knots, brightness and shape over timescales of years, indicating the dynamical character of these bipolar outflows. In addition to these ejections the protostar can also gain some mass by the process of accretion. The main concepts here are: (i) as the protostar nebula contract ...
AMUSE-Virgo AGN Multi-wavelength Survey
... Targets 100 early type galaxies which compose the HST ACS Virgo Cluster Survey (ACSVCS, Cote’ et al 04) - 84 new targets with Chandra ACIS-S (454 ksec; PI: Treu) + 16 archival ...
... Targets 100 early type galaxies which compose the HST ACS Virgo Cluster Survey (ACSVCS, Cote’ et al 04) - 84 new targets with Chandra ACIS-S (454 ksec; PI: Treu) + 16 archival ...
New Astrophysical Opportunities Exploiting Spatio-Temporal Optical Correlations
... nuclear activity. The VLTI has succeeded in resolving structures in the AGN torus at midinfrared wavelengths [23] on scales of 30 milli-arcsecond. On the other hand, the blue optical continuum emission is dominated by thermal emission from the inner accretion disk (the source of the “big blue bump” ...
... nuclear activity. The VLTI has succeeded in resolving structures in the AGN torus at midinfrared wavelengths [23] on scales of 30 milli-arcsecond. On the other hand, the blue optical continuum emission is dominated by thermal emission from the inner accretion disk (the source of the “big blue bump” ...
Lecture 29 Our Galaxy: "Milky Way"
... Galactic Rotation Galactic material must be in some kind of orbit around the center, or gravity would pull everything into the center! • Rotation of Galaxy is real tough to measure (can't actually see rotation in our lifetime), but get a rough idea as follows, mainly from doppler radial velocities: ...
... Galactic Rotation Galactic material must be in some kind of orbit around the center, or gravity would pull everything into the center! • Rotation of Galaxy is real tough to measure (can't actually see rotation in our lifetime), but get a rough idea as follows, mainly from doppler radial velocities: ...
MEASURING THE STARS
... • Such a plot is called the H-‐R diagram • H & R discovered that the stars were not randomly distributed in the H-‐R diagram ...
... • Such a plot is called the H-‐R diagram • H & R discovered that the stars were not randomly distributed in the H-‐R diagram ...
Physics 130 Name
... b.) its spectrum has the same shape as that of a laboratory black body, typically at a temperature of about 150K. c.) no light can escape from it because of its powerful gravitational field. d.) the gravitational field is so high that the wavelength of the emitted light is shifted to radio wavelengt ...
... b.) its spectrum has the same shape as that of a laboratory black body, typically at a temperature of about 150K. c.) no light can escape from it because of its powerful gravitational field. d.) the gravitational field is so high that the wavelength of the emitted light is shifted to radio wavelengt ...
Binary Stars/Star Clusters
... Assumption: all stars of a given cluster formed from same Nebula ∴ All stars of a single cluster are (1) the same distance from Earth & (2) the same age ...
... Assumption: all stars of a given cluster formed from same Nebula ∴ All stars of a single cluster are (1) the same distance from Earth & (2) the same age ...
Mixing in massive stellar mergers
... resulting from a head-on collision of two massive main-sequence stars, which we call parent stars. To begin with, we consider fluid elements at the centre of each parent star and determine which one will settle in the centre of the collision product. For this purpose, we both make an initial estimat ...
... resulting from a head-on collision of two massive main-sequence stars, which we call parent stars. To begin with, we consider fluid elements at the centre of each parent star and determine which one will settle in the centre of the collision product. For this purpose, we both make an initial estimat ...
Origin of close binary systems
... other relevant considerations (not today) - formation clues from observed multiplicity trends in different stellar environments - consequences of multiplicities for runaways, non-local supernovae, starburst population synthesis including exotic products of binary stellar evolution (high mass X-ray ...
... other relevant considerations (not today) - formation clues from observed multiplicity trends in different stellar environments - consequences of multiplicities for runaways, non-local supernovae, starburst population synthesis including exotic products of binary stellar evolution (high mass X-ray ...
The DB gap and a new class of pulsating white dwarfs
... of white dwarfs with helium dominant atmospheres are described and a new class of pulsating white dwarfs, named the hot-DAV stars, is predicted from these scenarios. One pulsating DA white dwarf, being consistent with the prediction, has been discovered indeed. ...
... of white dwarfs with helium dominant atmospheres are described and a new class of pulsating white dwarfs, named the hot-DAV stars, is predicted from these scenarios. One pulsating DA white dwarf, being consistent with the prediction, has been discovered indeed. ...
Document
... also proceeds efficiently and enables an equilibrium between electrons, protons, and neutrons. But at high densities, when electron Fermi energy is high and the electron produced by -decay does not have sufficient energy, the inverse decay proceeds to primarily create more neutrons. ...
... also proceeds efficiently and enables an equilibrium between electrons, protons, and neutrons. But at high densities, when electron Fermi energy is high and the electron produced by -decay does not have sufficient energy, the inverse decay proceeds to primarily create more neutrons. ...
Cosmology Notes
... Hydrogen combines to make helium Hydrogen is used up and star shrinks, heats up more and burns helium to form element up to the size of iron Once helium is used up star collapses and forms larger elements in a super nova ...
... Hydrogen combines to make helium Hydrogen is used up and star shrinks, heats up more and burns helium to form element up to the size of iron Once helium is used up star collapses and forms larger elements in a super nova ...
Cosmology – The Origin and Evolution of the Universe
... plates, only those virtual photons whose wavelengths fit a whole number of times into the gap can be counted when calculating the vacuum energy, the rest destructively interfere. • Thus, the energy density between the plates decreases as the plates are moved closer, which implies that there is a sma ...
... plates, only those virtual photons whose wavelengths fit a whole number of times into the gap can be counted when calculating the vacuum energy, the rest destructively interfere. • Thus, the energy density between the plates decreases as the plates are moved closer, which implies that there is a sma ...
Thermal emission and internal heating processes in millisecond
... • Observed UV emission of PSR J0437-4715 may be due to rotochemical heating • The same emission can be used to constrain |dG/dt|: – competitive with best existing constraints if fast cooling processes could be ruled out ...
... • Observed UV emission of PSR J0437-4715 may be due to rotochemical heating • The same emission can be used to constrain |dG/dt|: – competitive with best existing constraints if fast cooling processes could be ruled out ...
The Celestial Origin of Atoms
... Aims and aspirations of nuclear astrophysics The aim of nuclear astrophysics is threefold. Firstly, it seeks to determine the mechanisms whereby the various nuclear species occurring in nature are built up, from deuterium with its two nucleons to uranium with 238 nucleons. Secondly, it seeks to iden ...
... Aims and aspirations of nuclear astrophysics The aim of nuclear astrophysics is threefold. Firstly, it seeks to determine the mechanisms whereby the various nuclear species occurring in nature are built up, from deuterium with its two nucleons to uranium with 238 nucleons. Secondly, it seeks to iden ...
Slide 1
... possible cause of bar creation is tidal disruptions between galaxies. The bar structure decays over time ...
... possible cause of bar creation is tidal disruptions between galaxies. The bar structure decays over time ...
A neutron star with a carbon atmosphere in the Cassiopeia A
... data from two studies of Cas A, both using the ACIS-S charge-coupled device which provides spatial and spectral information.11 A series of Chandra observations, totalling 1 megasecond, was performed in 2004 to study the supernova remnant12 ; these are referred to here as the Hwang data. A shorter (7 ...
... data from two studies of Cas A, both using the ACIS-S charge-coupled device which provides spatial and spectral information.11 A series of Chandra observations, totalling 1 megasecond, was performed in 2004 to study the supernova remnant12 ; these are referred to here as the Hwang data. A shorter (7 ...
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.