Rotational effects on the oscillation frequencies of newly born proto
... FMP, it has been shown that these frequencies change during the first minute of life of a proto-neutron star (PNS) born in a gravitational collapse, and that the changes are mainly due to neutrino diffusion and thermalisation processes which smooth out the high entropy gradients that develop in the ...
... FMP, it has been shown that these frequencies change during the first minute of life of a proto-neutron star (PNS) born in a gravitational collapse, and that the changes are mainly due to neutrino diffusion and thermalisation processes which smooth out the high entropy gradients that develop in the ...
Statistical analysis of stellar evolution
... cluster is described in Section 5, followed by discussion in Section 6. 2. Stellar evolution. 2.1. Basic evolutionary model and color-magnitude diagrams. Stars are believed to be formed when the dense parts of a molecular cloud collapse into a ball ...
... cluster is described in Section 5, followed by discussion in Section 6. 2. Stellar evolution. 2.1. Basic evolutionary model and color-magnitude diagrams. Stars are believed to be formed when the dense parts of a molecular cloud collapse into a ball ...
Star Formation in the Milky Way - HubbleSOURCE
... initial cloud at T=0 evolving over ~250,000 years to collapse and fragment form a small cluster of ~1200 stars. Some of the low mass members are formed in the inner cloud regions and ejected into outer regions of the ...
... initial cloud at T=0 evolving over ~250,000 years to collapse and fragment form a small cluster of ~1200 stars. Some of the low mass members are formed in the inner cloud regions and ejected into outer regions of the ...
Lecture 2
... a straight line (main sequence): log(L) = constant . log(Teff). • Stars that have the same luminosity as dimmer main sequence stars, but are to the leg of them (hoRer) on the HR diagram, have smaller surface areas (smaller radii). • Bright, cool stars are very large (Red Giants) and lie above ...
... a straight line (main sequence): log(L) = constant . log(Teff). • Stars that have the same luminosity as dimmer main sequence stars, but are to the leg of them (hoRer) on the HR diagram, have smaller surface areas (smaller radii). • Bright, cool stars are very large (Red Giants) and lie above ...
Beyond the iron group: Heavy metals in hot subdwarfs
... (i.e. whether they are formed by the r- or s-process). Clearly they can not be formed in these hot subdwarfs, but their presence can, however, be used to shed some light on some of the other chemical peculiarities found in these stars. It has long been know that silicon in sdB stars show peculiar be ...
... (i.e. whether they are formed by the r- or s-process). Clearly they can not be formed in these hot subdwarfs, but their presence can, however, be used to shed some light on some of the other chemical peculiarities found in these stars. It has long been know that silicon in sdB stars show peculiar be ...
The solution of the radiative transfer equation in axial symmetry
... the radiative transfer equation (RTE) in a more general geometry than planeparallel or spherically symmetric ones. There are not too many methods available for solving the multidimensional problem. For optically thin regions, the Monte Carlo method [21] may be used. On the other hand, in the optical ...
... the radiative transfer equation (RTE) in a more general geometry than planeparallel or spherically symmetric ones. There are not too many methods available for solving the multidimensional problem. For optically thin regions, the Monte Carlo method [21] may be used. On the other hand, in the optical ...
Dynamical Mass Measurements of Pre-Main
... AS technique will rely in large part on interferometric data. The angular resolution limits of these observations are more than sufficient to achieve excellent mass-measurement precisions for PMS SBs in nearby star-forming regions. The limitations are that both components must “fit” within the beam ...
... AS technique will rely in large part on interferometric data. The angular resolution limits of these observations are more than sufficient to achieve excellent mass-measurement precisions for PMS SBs in nearby star-forming regions. The limitations are that both components must “fit” within the beam ...
C, N, O abundances and carbon isotope ratios in evolved stars of
... this to the incomplete adequacy of Kurucz atmospheric models for cool giants), the [Fe/H] value of the star Cr 261 1871, which is located at the red giant branch-tip, is slightly peculiar because it is more than 0.2 dex lower than of other cluster stars. Its carbon and nitrogen to iron ratios are in ...
... this to the incomplete adequacy of Kurucz atmospheric models for cool giants), the [Fe/H] value of the star Cr 261 1871, which is located at the red giant branch-tip, is slightly peculiar because it is more than 0.2 dex lower than of other cluster stars. Its carbon and nitrogen to iron ratios are in ...
HOW TO MAKE A SINGLETON sdB STAR VIA ACCELERATED STELLAR... Drew Clausen and Richard A. Wade
... the tip of the red giant branch (RGB). Many formation channels invoke binary mass transfer to account for the loss of the H-rich envelope (e.g., Mengel et al. 1976; Han et al. 2002, 2003). This mass-loss mechanism is supported by observations that show that 69% of sdBs are found in close binaries (M ...
... the tip of the red giant branch (RGB). Many formation channels invoke binary mass transfer to account for the loss of the H-rich envelope (e.g., Mengel et al. 1976; Han et al. 2002, 2003). This mass-loss mechanism is supported by observations that show that 69% of sdBs are found in close binaries (M ...
Beyond the iron group: heavy metals in hot subdwarfs
... this Letter (i.e. whether they are formed by the r- or s-process). Clearly they can not be formed in these hot subdwarfs, but their presence can, however, be used to shed some light on some of the other chemical peculiarities found in these stars. It has long been know that silicon in sdB stars show ...
... this Letter (i.e. whether they are formed by the r- or s-process). Clearly they can not be formed in these hot subdwarfs, but their presence can, however, be used to shed some light on some of the other chemical peculiarities found in these stars. It has long been know that silicon in sdB stars show ...
Transport of angular momentum in massive stars
... number with respect to their progress on their main sequence evolution. Then for the first, in their main sequence evolution less progressed, group the surface rotation velocity can be predicted for a later stage. This prediction is based on assumptions about the transport of angular momentum in sta ...
... number with respect to their progress on their main sequence evolution. Then for the first, in their main sequence evolution less progressed, group the surface rotation velocity can be predicted for a later stage. This prediction is based on assumptions about the transport of angular momentum in sta ...
1. INTRODUCTION - Institut für Theoretische Astrophysik
... 2. At the bottom of the atmosphere, we introduce sinusoidal acoustic waves generated by a piston. The waves are followed to the point of shock formation and beyond. 3. The shocks are treated as discontinuities and are allowed to grow to arbitrary strength. Since we utilize the method of characterist ...
... 2. At the bottom of the atmosphere, we introduce sinusoidal acoustic waves generated by a piston. The waves are followed to the point of shock formation and beyond. 3. The shocks are treated as discontinuities and are allowed to grow to arbitrary strength. Since we utilize the method of characterist ...
Determining distances to stars statistically from photometry
... communication between the processors, which is not possible at this time. Instead, we parallelize the calculations by sending a single likelihood calculation (including the whole ~ to each volunteer. These work units can take a couple minutes (if integral for a given Q) the work unit is sent to a GP ...
... communication between the processors, which is not possible at this time. Instead, we parallelize the calculations by sending a single likelihood calculation (including the whole ~ to each volunteer. These work units can take a couple minutes (if integral for a given Q) the work unit is sent to a GP ...
4. Stars and resolved stellar populations
... III]/Hβ ratio is a crucial indicator of fast shocks with speed above 100 km/s, while [S II] 6716/6731, [NII]/[O I], and [SII]/[O I] provide direct estimates of, respectively, the jet electronic density, ionization fraction and temperature, with much less dependence on the heating process than ratios ...
... III]/Hβ ratio is a crucial indicator of fast shocks with speed above 100 km/s, while [S II] 6716/6731, [NII]/[O I], and [SII]/[O I] provide direct estimates of, respectively, the jet electronic density, ionization fraction and temperature, with much less dependence on the heating process than ratios ...
Comparing stars - The Open University
... We have added to Figure 5 an indication of the colour associated with each temperature. However, to the unaided eye, star colours are in many cases not very striking. This is partly because too little light is being received for our colour vision to be strongly excited, and partly because the colour ...
... We have added to Figure 5 an indication of the colour associated with each temperature. However, to the unaided eye, star colours are in many cases not very striking. This is partly because too little light is being received for our colour vision to be strongly excited, and partly because the colour ...
Rosolowsky
... • Comparing Virial and CO masses over a range of galactic radii in M33 • No significant trend with radius • No change in X due only to: – Metallicity (0.6 dex) – ISRF (1 dex) – Midplane hydrostatic pressure (1 dex) ...
... • Comparing Virial and CO masses over a range of galactic radii in M33 • No significant trend with radius • No change in X due only to: – Metallicity (0.6 dex) – ISRF (1 dex) – Midplane hydrostatic pressure (1 dex) ...
Peak Bagging of red giant stars observed by Kepler: first results with
... red giants (RGs) has encountered a substantial increase, especially thanks to the advent of the spacebased photometric missions CoRoT (e.g. [20,19]) and Kepler (e.g. [16, 15]), where the latter allowed also for the study of RGs in open clusters (e.g. [25,7]). The discovery of so-called mixed modes [ ...
... red giants (RGs) has encountered a substantial increase, especially thanks to the advent of the spacebased photometric missions CoRoT (e.g. [20,19]) and Kepler (e.g. [16, 15]), where the latter allowed also for the study of RGs in open clusters (e.g. [25,7]). The discovery of so-called mixed modes [ ...
Infrared Photometry of Red Supergiants in Young Clusters in the
... discussion has relied upon these IR colours and the B−V colours of Robertson (1974). The observed properties of the RSG population has featured prominently in many of the subsequent discussions of the evolutionary implications of the populations of these clusters. Many of these discussions have to s ...
... discussion has relied upon these IR colours and the B−V colours of Robertson (1974). The observed properties of the RSG population has featured prominently in many of the subsequent discussions of the evolutionary implications of the populations of these clusters. Many of these discussions have to s ...
Astrophysics with the Computer: Propagation of Ionization Fronts in
... which get absorbed by the gas. After about one recombination time scale (τrek = 1/ne α, see below) an equilibrium state is reached and the front stops moving. Then we have reached the phase of a stationary Strömgren sphere. Very similar phenomena occur when the central star of a planetary nebula on ...
... which get absorbed by the gas. After about one recombination time scale (τrek = 1/ne α, see below) an equilibrium state is reached and the front stops moving. Then we have reached the phase of a stationary Strömgren sphere. Very similar phenomena occur when the central star of a planetary nebula on ...
Abundance Anomalies In Tidal Disruption Events
... in Gaskell & Rojas Lobos (2014), the key at Solar metallicity lies in finding a density regime where line opacities can drive the line ratios close to the thermal limit where the HeII 4686Å line is (6563/4686)4 = 3.8 times stronger than Hα. Strubbe & Murray (2015) broadly argue that the underlying ...
... in Gaskell & Rojas Lobos (2014), the key at Solar metallicity lies in finding a density regime where line opacities can drive the line ratios close to the thermal limit where the HeII 4686Å line is (6563/4686)4 = 3.8 times stronger than Hα. Strubbe & Murray (2015) broadly argue that the underlying ...
Physics of Stars and the Measurement Data: Part III
... cells, which we have neglected for good reason. The barrier of the electron cloud near the nucleus will prevent its β-decay, if it has less energy. As a result, the nucleus that exhibit β-activity in the atomic matter will not disintegrate in plasma. Of course, this barrier can be overcome due to th ...
... cells, which we have neglected for good reason. The barrier of the electron cloud near the nucleus will prevent its β-decay, if it has less energy. As a result, the nucleus that exhibit β-activity in the atomic matter will not disintegrate in plasma. Of course, this barrier can be overcome due to th ...
Models of red giants in the CoRoT asteroseismology fields
... Solar reference values from M14 are Δν = 135.1 μHz, νmax, = 3090 μHz and T eff, = 5777 K. As the Hipparcos parallax, π, is available for most of the stars studied here, we can derive the stellar luminosity from the apparent magnitude in V-band, and then the stellar radius. The bolometric correctio ...
... Solar reference values from M14 are Δν = 135.1 μHz, νmax, = 3090 μHz and T eff, = 5777 K. As the Hipparcos parallax, π, is available for most of the stars studied here, we can derive the stellar luminosity from the apparent magnitude in V-band, and then the stellar radius. The bolometric correctio ...
Document
... Density profile decides how deep the pulsations penetrate in the star. (Deeper the penetration ...
... Density profile decides how deep the pulsations penetrate in the star. (Deeper the penetration ...
Fulltext
... choose to stay inside a bubble (“bag”) in order to minimize the total energy of the system. (If such bubble does not exist, quarks will first dig a bubble and then stay inside it.) To obey Pauli exclusion principle for fermions, we may adopt the Thomas-Fermi approximation to treat contributions from ...
... choose to stay inside a bubble (“bag”) in order to minimize the total energy of the system. (If such bubble does not exist, quarks will first dig a bubble and then stay inside it.) To obey Pauli exclusion principle for fermions, we may adopt the Thomas-Fermi approximation to treat contributions from ...