Chapter: The Evolution of Binary Systems
... in the range of 30 % to 50 % (where the binary fraction is higher for more massive stars; see, e.g., Duquennoy & Mayor 1991; Kobulnicky & Fryer 2007). A very approximate period distribution, and very useful rule of thumb, is that the distribution in log Porb is logarithmically flat (i.e., f (log Por ...
... in the range of 30 % to 50 % (where the binary fraction is higher for more massive stars; see, e.g., Duquennoy & Mayor 1991; Kobulnicky & Fryer 2007). A very approximate period distribution, and very useful rule of thumb, is that the distribution in log Porb is logarithmically flat (i.e., f (log Por ...
General Module information
... – the physical effects leading to the red giant branch Qualitatively explain how the evolution of low mass stars differ from the above. Explain qualitatively how the post-RGB evolution of low mass stars leads to the formation of planetary nebulas and white dwarfs. Explain how the asymptotic giant br ...
... – the physical effects leading to the red giant branch Qualitatively explain how the evolution of low mass stars differ from the above. Explain qualitatively how the post-RGB evolution of low mass stars leads to the formation of planetary nebulas and white dwarfs. Explain how the asymptotic giant br ...
they might be giants: luminosity class, planet occurrence, and planet
... star. Likewise, the transit signal produced by a planet of a given radius - and hence its detectability around a star in the survey - also depends on stellar radius. If some target stars are actually larger or even giant stars, then planets are less likely to be detected in that sample, which means ...
... star. Likewise, the transit signal produced by a planet of a given radius - and hence its detectability around a star in the survey - also depends on stellar radius. If some target stars are actually larger or even giant stars, then planets are less likely to be detected in that sample, which means ...
Chapter 9 Early stages of evolution and the main sequence phase
... know how stars are formed, how can we hope to understand their evolution? The reason that stellar evolution is a much more quantitative and predictive branch of astrophysics than star formation was already alluded to in Chapter 7. Once a recently formed star settles into hydrostatic and thermal equi ...
... know how stars are formed, how can we hope to understand their evolution? The reason that stellar evolution is a much more quantitative and predictive branch of astrophysics than star formation was already alluded to in Chapter 7. Once a recently formed star settles into hydrostatic and thermal equi ...
Max Planck Institute for Gravitational Physics
... RELAXATION TIMESCALE Gravity is a LONG-RANGE force → cumulative influence on each star/body of distant stars/bodies is important: often more important than influence of close stars/bodies Let us consider a IDEALIZED galaxy of N identical stars with mass m, size R and uniform density Let us focus on ...
... RELAXATION TIMESCALE Gravity is a LONG-RANGE force → cumulative influence on each star/body of distant stars/bodies is important: often more important than influence of close stars/bodies Let us consider a IDEALIZED galaxy of N identical stars with mass m, size R and uniform density Let us focus on ...
On the onset of runaway stellar collisions in dense star clusters I
... studying young star clusters such as R136, MGG11 and Arches (Massey & Hunter 1998; Figer et al. 2002; McCrady et al. 2005), and young star clusters are thought to be born with high concentration (Merritt et al. 2004). In addition, high concentration is a necessary condition for clusters which can ex ...
... studying young star clusters such as R136, MGG11 and Arches (Massey & Hunter 1998; Figer et al. 2002; McCrady et al. 2005), and young star clusters are thought to be born with high concentration (Merritt et al. 2004). In addition, high concentration is a necessary condition for clusters which can ex ...
The UKIRT Infrared Deep Sky Survey ZY JHK Photometric System
... thus differential in nature and mimics the procedure undertaken when performing actual photometric observations, calibrated by observations of standard stars. The shape of the throughput function is the key element in the calculation, although, for all but the most pathological of target SEDs, error ...
... thus differential in nature and mimics the procedure undertaken when performing actual photometric observations, calibrated by observations of standard stars. The shape of the throughput function is the key element in the calculation, although, for all but the most pathological of target SEDs, error ...
A massive hypergiant star as the progenitor of the supernova SN
... shells4,28, along with very luminous optical displays, during which the luminosity of the star may increase by an order of magnitude or more. These events (sometimes called supernova impostors26) can therefore be confused with genuine supernova explosions. b, Collisions between a faster massive ejec ...
... shells4,28, along with very luminous optical displays, during which the luminosity of the star may increase by an order of magnitude or more. These events (sometimes called supernova impostors26) can therefore be confused with genuine supernova explosions. b, Collisions between a faster massive ejec ...
LATE STAGES OF CLOSE BINARY SYSTEMS 1. Introduction The X
... 1976). This limit may, in real life, be somewhat higher still if one takes into account that helium stars more massive than about 4 A f o r 5Af are likely to be identified with WolfRayet stars, which are observed to undergo substantial mass loss by stellar wind. Mass loss rates between \QT*M^yx' and ...
... 1976). This limit may, in real life, be somewhat higher still if one takes into account that helium stars more massive than about 4 A f o r 5Af are likely to be identified with WolfRayet stars, which are observed to undergo substantial mass loss by stellar wind. Mass loss rates between \QT*M^yx' and ...
The star-forming environment of an ultraluminous X-ray
... of the spiral galaxy NGC 4559, using the HST Wide Field Planetary Camera 2 (WFPC2), XMM–Newton/Optical Monitor and ground-based data. We find that the ULX is located near a small group of OB stars, but is not associated with any massive young clusters nor with any extraordinary massive stars. The br ...
... of the spiral galaxy NGC 4559, using the HST Wide Field Planetary Camera 2 (WFPC2), XMM–Newton/Optical Monitor and ground-based data. We find that the ULX is located near a small group of OB stars, but is not associated with any massive young clusters nor with any extraordinary massive stars. The br ...
mass transfer in close, rapidly accreting protobinaries
... these systems formed at close to their current separations, or possibly even closer, since conservation of energy dictates that mass loss from winds during main-sequence evolution widens the orbits of massive binaries. This means that systems such as WR 20a, D33 J013346.2+304439.9, and the SMC binar ...
... these systems formed at close to their current separations, or possibly even closer, since conservation of energy dictates that mass loss from winds during main-sequence evolution widens the orbits of massive binaries. This means that systems such as WR 20a, D33 J013346.2+304439.9, and the SMC binar ...
The 8190-A sodium doublet in cataclysmic variables
... The red TiO bands, and possibly KI AA7664-, 7698-A lines in absorption, are detected as well as the Na I doublet. The infrared Ca II triplet is also in absorption; since the Balmer lines show no absorption components to suggest that the system has recently been in outburst, the Ca II triplet probabl ...
... The red TiO bands, and possibly KI AA7664-, 7698-A lines in absorption, are detected as well as the Na I doublet. The infrared Ca II triplet is also in absorption; since the Balmer lines show no absorption components to suggest that the system has recently been in outburst, the Ca II triplet probabl ...
Giant planet and brown dwarf formation
... is based on a slighly revised version of the Chabrier (2003) IMF (Chabrier, 2003) (see Chabrier, 2005). The observations include in particular the recent results from the WISE survey, which nearly reaches the bottom end of the BD mass distribution (Tef f < 500 K) in the field (Kirkpatrick et al., 20 ...
... is based on a slighly revised version of the Chabrier (2003) IMF (Chabrier, 2003) (see Chabrier, 2005). The observations include in particular the recent results from the WISE survey, which nearly reaches the bottom end of the BD mass distribution (Tef f < 500 K) in the field (Kirkpatrick et al., 20 ...
edmund c. stoner and the discovery of the maximum mass of white
... to the pressure given by the extreme relativistic equation at the same density. For a larger mass, he applied this relativistic equation to a central region of the star, and the non-relativistic equation for an external region of the star bounded by a surface defined when these two equations gave the ...
... to the pressure given by the extreme relativistic equation at the same density. For a larger mass, he applied this relativistic equation to a central region of the star, and the non-relativistic equation for an external region of the star bounded by a surface defined when these two equations gave the ...
Reconciling Dwarf Galaxies with LCDM Cosmology Andrew Wetzel F RE
... massive halo in each box. We compare the relation if all baryons became also compare a completely different version of SPH (with a different set stars (M∗ = fb Mhalo ; dotted) and the observationally inferred relationship of hydrodynamic equations), which is known to differ significantly as in deter ...
... massive halo in each box. We compare the relation if all baryons became also compare a completely different version of SPH (with a different set stars (M∗ = fb Mhalo ; dotted) and the observationally inferred relationship of hydrodynamic equations), which is known to differ significantly as in deter ...
ms
... from the same source give rise to highly reproducible emitting areas, strongly supporting the hypothesis that the entire neutron star surface is emitting during the cooling phase. Because of this, the cooling tails of X-ray bursts can be analyzed to measure the angular size of the neutron star, whic ...
... from the same source give rise to highly reproducible emitting areas, strongly supporting the hypothesis that the entire neutron star surface is emitting during the cooling phase. Because of this, the cooling tails of X-ray bursts can be analyzed to measure the angular size of the neutron star, whic ...
RESEARCH STATEMENT Chromospheres and winds
... differ from each other and vary between eclipse cycles. Comparisons between the supergiants in ζ Aurigae, 31 Cyg and 32 Cyg will be important to our understanding of evolved stars because their chromospheric features behave quite differently even though nominally the supergiants are very similar in ...
... differ from each other and vary between eclipse cycles. Comparisons between the supergiants in ζ Aurigae, 31 Cyg and 32 Cyg will be important to our understanding of evolved stars because their chromospheric features behave quite differently even though nominally the supergiants are very similar in ...
how dry is the brown dwarf desert? quantifying the
... The triangles in Figure 1 indicate that the ones left out are spread more or less evenly in B V space spanned by the gray parallelogram. Similarly in Figure 2, 1295 (= 3296–2001), or 39%, are not included in any Doppler target list, but the triangles show that more K stars than FG stars have not b ...
... The triangles in Figure 1 indicate that the ones left out are spread more or less evenly in B V space spanned by the gray parallelogram. Similarly in Figure 2, 1295 (= 3296–2001), or 39%, are not included in any Doppler target list, but the triangles show that more K stars than FG stars have not b ...
Finite Temperature Effects in the White Dwarf - Padis
... This thesis is in the context of the physics astrophysics of compact stars. In this work we explore in particular the thermal properties of white dwarfs and neutron stars. As we will show in chapter 3, the mass-radius relation of white dwarfs in the zero-temperature approximation deviates considerab ...
... This thesis is in the context of the physics astrophysics of compact stars. In this work we explore in particular the thermal properties of white dwarfs and neutron stars. As we will show in chapter 3, the mass-radius relation of white dwarfs in the zero-temperature approximation deviates considerab ...
Neutron stars as probes of extreme energy density matter
... 2GM = c2 R in the characteristic mass M vs. characteristic distance R diagram of the objects in our Universe (G is the Newton’s gravitational constant and c is the speed of light) [1]. Observed neutron star masses lie in the range 1−2M , whereas their radii are about 10−15 km so that GM/c2 R ∼ 0.1− ...
... 2GM = c2 R in the characteristic mass M vs. characteristic distance R diagram of the objects in our Universe (G is the Newton’s gravitational constant and c is the speed of light) [1]. Observed neutron star masses lie in the range 1−2M , whereas their radii are about 10−15 km so that GM/c2 R ∼ 0.1− ...
WFIRSTSurveyScience
... A space-based near-IR survey of the outer galaxy can overcome many of these problems and allow use of the Milky Way as a laboratory for how the star-formation process depends on metallicity, gas surface density and triggering mechanisms. The most distant star-forming regions in the galaxy are expect ...
... A space-based near-IR survey of the outer galaxy can overcome many of these problems and allow use of the Milky Way as a laboratory for how the star-formation process depends on metallicity, gas surface density and triggering mechanisms. The most distant star-forming regions in the galaxy are expect ...
Article PDF - IOPscience
... provided non-conservative mass transfer is allowed. Specifically, the donor-mass lower limit and orbital period measured for M82 X-2 lie near the most probable values predicted by population synthesis models, and systems such as M82 X-2 should exist in approximately 13% of the galaxies with a star fo ...
... provided non-conservative mass transfer is allowed. Specifically, the donor-mass lower limit and orbital period measured for M82 X-2 lie near the most probable values predicted by population synthesis models, and systems such as M82 X-2 should exist in approximately 13% of the galaxies with a star fo ...
First axion bounds from a pulsating helium
... Chromodynamics has as consequence the existence of axions, hypothetical weakly interacting particles whose mass is constrained to be on the sub-eV range. If these particles exist and interact with electrons, they would be emitted from the dense interior of white dwarfs, becoming an important energy ...
... Chromodynamics has as consequence the existence of axions, hypothetical weakly interacting particles whose mass is constrained to be on the sub-eV range. If these particles exist and interact with electrons, they would be emitted from the dense interior of white dwarfs, becoming an important energy ...
SHELL BURNING STARS: Red Giants and Red Supergiants
... At some point the rate of energy release due to helium burning becomes important for the heat balance near the center, and leads to an additional increase of the central temperature. This rise in temperature does not produce any increase in gas pressure, because pressure of degenerate gas does not d ...
... At some point the rate of energy release due to helium burning becomes important for the heat balance near the center, and leads to an additional increase of the central temperature. This rise in temperature does not produce any increase in gas pressure, because pressure of degenerate gas does not d ...
Lecture 9: Supernovae
... The light-curve behaved exactly as expected: after the initial increase, it faded quickly until June 1987. Then it settled into a much slower fade, of about 1% a day, for two years. This corresponds exactly to the laboratory-measured half-life of 56 Co (77 days), which is the result of the (rapid) d ...
... The light-curve behaved exactly as expected: after the initial increase, it faded quickly until June 1987. Then it settled into a much slower fade, of about 1% a day, for two years. This corresponds exactly to the laboratory-measured half-life of 56 Co (77 days), which is the result of the (rapid) d ...