Stars Stellar Lifetimes Life cycles of low
... in balance Stars attempt to maintain equilibrium by striking a balance between the gravity of their enormous mass and the pressure produced by the energy of fusion reactions. A main sequence star is in equilibrium as Hydrogen burning supports it against gravitational collapse. What happens as the hy ...
... in balance Stars attempt to maintain equilibrium by striking a balance between the gravity of their enormous mass and the pressure produced by the energy of fusion reactions. A main sequence star is in equilibrium as Hydrogen burning supports it against gravitational collapse. What happens as the hy ...
Resultados del Concurso 2008A para Observaciones en
... brown dwarfs and planets orbiting post-red giant branch “hot subdwarf” stars implies that the substellar objects are not only sufficient for ejecting the outer layers of a red giant’s atmosphere, but that they can also survive the engulfment phase. Thirty-six new eclipsing hot subdwarf binaries with ...
... brown dwarfs and planets orbiting post-red giant branch “hot subdwarf” stars implies that the substellar objects are not only sufficient for ejecting the outer layers of a red giant’s atmosphere, but that they can also survive the engulfment phase. Thirty-six new eclipsing hot subdwarf binaries with ...
The Initial Mass Function
... SmNW has too much accretion luminosity, no new stars are formed and the ones present continue growing, this displaces the IMF to larger masses. The gas is at higher T than in Tu case. Incorporating outflows has produced hypothesized result. Tu: 10% mass in stars ...
... SmNW has too much accretion luminosity, no new stars are formed and the ones present continue growing, this displaces the IMF to larger masses. The gas is at higher T than in Tu case. Incorporating outflows has produced hypothesized result. Tu: 10% mass in stars ...
Pan-Planets: Searching for hot Jupiters around cool dwarfs⋆
... −0.02 )% in case one of our candidates turns out to be a real detection. If, however, none of our candidates turn out to be true planets, we are able to put an upper limit of 0.34% with a 95% confidence on the hot Jupiter occurrence rate of M dwarfs. This limit is a significant improvement over prev ...
... −0.02 )% in case one of our candidates turns out to be a real detection. If, however, none of our candidates turn out to be true planets, we are able to put an upper limit of 0.34% with a 95% confidence on the hot Jupiter occurrence rate of M dwarfs. This limit is a significant improvement over prev ...
Master Thesis - Sterrenkunde RU Nijmegen
... of potential energy, which heats up the outer parts of the star. The star explodes as a supernova and the core either end up as a neutron star or a black hole. Stars with a mass less then ∼0.8M haven’t had time yet to evolve from the main-sequence, but when they do, they are not hot enough to fuse ...
... of potential energy, which heats up the outer parts of the star. The star explodes as a supernova and the core either end up as a neutron star or a black hole. Stars with a mass less then ∼0.8M haven’t had time yet to evolve from the main-sequence, but when they do, they are not hot enough to fuse ...
double shell–burning
... • This double shell–burning stage never reaches equilibrium—fusion rate periodically spikes upward in a series of thermal pulses. • With each spike, convection dredges carbon up from core and transports it to surface. © 2010 Pearson Education, Inc. ...
... • This double shell–burning stage never reaches equilibrium—fusion rate periodically spikes upward in a series of thermal pulses. • With each spike, convection dredges carbon up from core and transports it to surface. © 2010 Pearson Education, Inc. ...
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... indi ating that they have not traveled far from their birth sites and they hen e must be young (Brandt & Podsiadlowski 1995). There is no eviden e for high mass X-ray binaries in old GCs or in undisturbed ellipti al galaxies. The lifetimes of LMXBs are not as well understood. It is lear that the LM ...
... indi ating that they have not traveled far from their birth sites and they hen e must be young (Brandt & Podsiadlowski 1995). There is no eviden e for high mass X-ray binaries in old GCs or in undisturbed ellipti al galaxies. The lifetimes of LMXBs are not as well understood. It is lear that the LM ...
San Diego Astronomy Association CONTENTS
... Stars In The Park will be held on Wednesday, November 6th and December 4th. Star party nights at the site in Tierra Del Sol will be on November 2nd, 9th, 30th, and December 7th and 28th . We will be at Vallecito Stage Station on November 9th for our last Camp With The Stars program for the year. On ...
... Stars In The Park will be held on Wednesday, November 6th and December 4th. Star party nights at the site in Tierra Del Sol will be on November 2nd, 9th, 30th, and December 7th and 28th . We will be at Vallecito Stage Station on November 9th for our last Camp With The Stars program for the year. On ...
11.1 Introduction
... During the free-fall collapse phase, the density within the cloud increases by many orders of magnitude. If the temperature remains approximately constant, then the Jeans mass criterion (eq.11.8) implies that the mass limit for instability decreases dramatically. Any initial density inhomogeneities ...
... During the free-fall collapse phase, the density within the cloud increases by many orders of magnitude. If the temperature remains approximately constant, then the Jeans mass criterion (eq.11.8) implies that the mass limit for instability decreases dramatically. Any initial density inhomogeneities ...
" Galaxy," Defined
... Although no single definition of galaxy will be optimal for all purposes, we propose a physically motivated definition that will facilitate studies of galaxies both in and out of a cosmological context: A galaxy is a gravitationally bound collection of stars whose properties cannot be explained by a ...
... Although no single definition of galaxy will be optimal for all purposes, we propose a physically motivated definition that will facilitate studies of galaxies both in and out of a cosmological context: A galaxy is a gravitationally bound collection of stars whose properties cannot be explained by a ...
The fraction of DA white dwarfs with kilo
... For one of our cases, LP 672−001 (WD 1105−048), Valyavin et al. (2006) confirm the presence of a kG magnetic field by measuring circular polarisation at Hα using the 6 m of the Special Astrophysical Observatory. On the other hand, none of the other 5 bright white dwarfs of their sample showed any si ...
... For one of our cases, LP 672−001 (WD 1105−048), Valyavin et al. (2006) confirm the presence of a kG magnetic field by measuring circular polarisation at Hα using the 6 m of the Special Astrophysical Observatory. On the other hand, none of the other 5 bright white dwarfs of their sample showed any si ...
Fossil Galaxies
... Astronomers and cosmologists have a problem on their hands. Their trusted computer simulations of the evolving universe predict that thousands of dwarf galaxies should currently exist in orbit around our Milky Way galaxy. However, only a few dozen dwarf galaxies have been observed. Called the “missi ...
... Astronomers and cosmologists have a problem on their hands. Their trusted computer simulations of the evolving universe predict that thousands of dwarf galaxies should currently exist in orbit around our Milky Way galaxy. However, only a few dozen dwarf galaxies have been observed. Called the “missi ...
BREATHING IN LOW MASS GALAXIES: A STUDY - N
... less than 100 Myr, which is much shorter than the dynamical time. Thus cooling does not significantly impede the collapse of the galaxy and formation of stars and thus the period is dominated by the dynamical time. For larger galaxies, star formation never completely ceases due to the reduced effect ...
... less than 100 Myr, which is much shorter than the dynamical time. Thus cooling does not significantly impede the collapse of the galaxy and formation of stars and thus the period is dominated by the dynamical time. For larger galaxies, star formation never completely ceases due to the reduced effect ...
white dwarf
... – irradiation of the stream and secondary by X-ray flux – more astrophysics in the post-shock flow models (such as the separation of electron and ion fluids) • Combinations of high quality data (e.g. eclipse mapping of spectra) and new astrophysical fluid computations will transform the field and al ...
... – irradiation of the stream and secondary by X-ray flux – more astrophysics in the post-shock flow models (such as the separation of electron and ion fluids) • Combinations of high quality data (e.g. eclipse mapping of spectra) and new astrophysical fluid computations will transform the field and al ...
Carbon monoxide in clouds at low metallicity in the dwarf irregular
... where stars form, but it has never been detected in galaxies in which the oxygen abundance relative to hydrogen is less than 20 per cent of that of the Sun, even though such ‘low-metallicity’ galaxies often form stars. This raises the question of whether stars can form in dense gas without molecules ...
... where stars form, but it has never been detected in galaxies in which the oxygen abundance relative to hydrogen is less than 20 per cent of that of the Sun, even though such ‘low-metallicity’ galaxies often form stars. This raises the question of whether stars can form in dense gas without molecules ...
Chapter 10: The Sun-
... • Binaries are the only guaranteed gravitational wave sources • Detection of NS-NS or NS-BH will lead to great advances in knowledge of EOS • Nuclear star clusters are promising factories for compact binaries • Many benefits of low frequency, including: Possible detection of white dwarfs Long lead t ...
... • Binaries are the only guaranteed gravitational wave sources • Detection of NS-NS or NS-BH will lead to great advances in knowledge of EOS • Nuclear star clusters are promising factories for compact binaries • Many benefits of low frequency, including: Possible detection of white dwarfs Long lead t ...
Population synthesis for double white dwarfs. I. Close - UvA-DARE
... companion has also evolved off the main sequence. This kind of evolution can only take place when the initial mass ratio is close to unity. Such a mass transfer phase has hitherto been described with the standard common envelope formalism; in the same way as when the companion is still a main sequen ...
... companion has also evolved off the main sequence. This kind of evolution can only take place when the initial mass ratio is close to unity. Such a mass transfer phase has hitherto been described with the standard common envelope formalism; in the same way as when the companion is still a main sequen ...
ppt - ciera
... fields reveals no new 530 s pulsars, so there is a <0.5% chance of finding a magnetar in any field (Nechita, Gaensler, Muno, et al. in prep). • The pulsar is well within the cluster, with a <10% chance of being an unrelated X-ray source. ...
... fields reveals no new 530 s pulsars, so there is a <0.5% chance of finding a magnetar in any field (Nechita, Gaensler, Muno, et al. in prep). • The pulsar is well within the cluster, with a <10% chance of being an unrelated X-ray source. ...
on the mass of the black hole in gs
... approximation was assumed, with limb-darkening coefficients taken from Al-Naimiy (1978) and a gravitational darkening coefficient of 0.08 (Lucy 1967), appropriate for an early to mid-K secondary (FMB). Simulations show that the use of Kurucz stellar atmospheres instead of a blackbody approximation c ...
... approximation was assumed, with limb-darkening coefficients taken from Al-Naimiy (1978) and a gravitational darkening coefficient of 0.08 (Lucy 1967), appropriate for an early to mid-K secondary (FMB). Simulations show that the use of Kurucz stellar atmospheres instead of a blackbody approximation c ...
arXiv:1102.4757v1 [astro-ph.SR] 23 Feb 2011
... to theoretical models, the change in orbital energy must be at least as large as the binding energy of the giant (see Paczynski 1976; Han et al. 2002, 2003). Detailed models of giants at the tip of the red-giant branch that will form sdB stars after the common envelope are given in Hu et al. (2007). ...
... to theoretical models, the change in orbital energy must be at least as large as the binding energy of the giant (see Paczynski 1976; Han et al. 2002, 2003). Detailed models of giants at the tip of the red-giant branch that will form sdB stars after the common envelope are given in Hu et al. (2007). ...
sun.galaxy.notes
... • Hot stars are ______ in color • Cooler stars are ______in color • An H-R diagram is a graph that relates star ________ to star ...
... • Hot stars are ______ in color • Cooler stars are ______in color • An H-R diagram is a graph that relates star ________ to star ...
Properties of long gamma-ray bursts from massive compact binaries
... form an accretion disc following core collapse. For each of these binaries, we expect a black hole to form via fall back. After the supernova, a neutron star of mass approximately 2 M forms. The remainder of the core’s mass is ejected in the explosion. Some of this ejecta is stalled by a reverse sh ...
... form an accretion disc following core collapse. For each of these binaries, we expect a black hole to form via fall back. After the supernova, a neutron star of mass approximately 2 M forms. The remainder of the core’s mass is ejected in the explosion. Some of this ejecta is stalled by a reverse sh ...
An absence of ex-companion stars in the type Ia supernova remnant
... Various candidate classes have been proposed (see Table 1 and Supplementary Information section 1), although arguments and counterarguments have resulted in no decisive solution. It is possible that the observed type Ia supernovae might have two comparable-sized progenitor classes21. In double-degen ...
... Various candidate classes have been proposed (see Table 1 and Supplementary Information section 1), although arguments and counterarguments have resulted in no decisive solution. It is possible that the observed type Ia supernovae might have two comparable-sized progenitor classes21. In double-degen ...
Presentation (PowerPoint File)
... Simulations of star formation in cores with r r-1.5 Equation of state: isothermal or barotropic above 10^-14 g cm-3 Isothermal collapse results in many small fragments; barotropic collapse in a few. In no case did a massive star form (although simulation ran only until ~ 10% of mass had gone into ...
... Simulations of star formation in cores with r r-1.5 Equation of state: isothermal or barotropic above 10^-14 g cm-3 Isothermal collapse results in many small fragments; barotropic collapse in a few. In no case did a massive star form (although simulation ran only until ~ 10% of mass had gone into ...