Chapter 9 Red Giant Evolution
... strong temperature dependence, the rise in temperature causes a rapid increase in the reaction rates and the fusion reactions run faster. 5. This in turn raises the temperature further and thus reaction rates, and so on (thermonuclear runaway). 6. The large thermal conductivity of degenerate matter ...
... strong temperature dependence, the rise in temperature causes a rapid increase in the reaction rates and the fusion reactions run faster. 5. This in turn raises the temperature further and thus reaction rates, and so on (thermonuclear runaway). 6. The large thermal conductivity of degenerate matter ...
The importance of radiative feedback for the stellar initial mass
... As each fragment accreted its central density and temperature increased, resulting in smaller and smaller time-steps. When the central density of a fragment exceeded 10−11 g cm−3 , it was replaced by a sink particle. In this paper, the evolution of a collapsing region of gas is similar except that t ...
... As each fragment accreted its central density and temperature increased, resulting in smaller and smaller time-steps. When the central density of a fragment exceeded 10−11 g cm−3 , it was replaced by a sink particle. In this paper, the evolution of a collapsing region of gas is similar except that t ...
The fourth catalogue of Population I Wolf
... These stars are believed to represent the minimum or quiescent state of Luminous Blue Variables (Smith et al. 1998), hereafter LBVs. A few other LMC stars classified O3If∗ /WN6-A (Walborn 1982a, 1986; Walborn & Blades 1997; Massey & Hunter 1998) also enter the Of/WN ...
... These stars are believed to represent the minimum or quiescent state of Luminous Blue Variables (Smith et al. 1998), hereafter LBVs. A few other LMC stars classified O3If∗ /WN6-A (Walborn 1982a, 1986; Walborn & Blades 1997; Massey & Hunter 1998) also enter the Of/WN ...
An improved classification of B[e]-type stars
... A fraction of the stars that show the B[e] phenomenon are clearly very young stars because they appear in star forming regions. These stars may appear as pre-main sequence stars and show, therefore, many characteristics of and are related to the Herbig Ae/Be stars, also called “HAeBe-stars” (Thé et ...
... A fraction of the stars that show the B[e] phenomenon are clearly very young stars because they appear in star forming regions. These stars may appear as pre-main sequence stars and show, therefore, many characteristics of and are related to the Herbig Ae/Be stars, also called “HAeBe-stars” (Thé et ...
The incidence of stellar mergers and mass gainers among massive
... to its thermal equilibrium structure while rotating near its Keplerian rotational velocity. It is assumed that the core of the most evolved star, which has the lowest entropy, sinks to the center of the merged star. In our standard simulation only a small fraction µmix = 0.1 of the hydrogen-rich env ...
... to its thermal equilibrium structure while rotating near its Keplerian rotational velocity. It is assumed that the core of the most evolved star, which has the lowest entropy, sinks to the center of the merged star. In our standard simulation only a small fraction µmix = 0.1 of the hydrogen-rich env ...
The Lagoon Nebula and its Vicinity
... cluster, so NGC 6530 is now always used to refer to the cluster rather than any surrounding nebulosity. We take NGC 6533 to refer to the H II region only, comprising NGC 6523 and 6526. H II region studies have generally concentrated on the brighter eastern core (i.e. NGC 6523), and so it is this des ...
... cluster, so NGC 6530 is now always used to refer to the cluster rather than any surrounding nebulosity. We take NGC 6533 to refer to the H II region only, comprising NGC 6523 and 6526. H II region studies have generally concentrated on the brighter eastern core (i.e. NGC 6523), and so it is this des ...
Chemical composition of halo and disk stars with
... based on a net of flux constant, homogeneous, LTE model atmospheres kindly supplied by Bengt Edvardsson, Uppsala. The models were computed with an updated version of the MARCS code of Gustafsson et al. (1975) using continuous opacities from Asplund et al. (1997) and including UV line blanketing as d ...
... based on a net of flux constant, homogeneous, LTE model atmospheres kindly supplied by Bengt Edvardsson, Uppsala. The models were computed with an updated version of the MARCS code of Gustafsson et al. (1975) using continuous opacities from Asplund et al. (1997) and including UV line blanketing as d ...
Bright 22 μm excess candidates from the wise all-sky
... the Near-Earth Object population (Wright et al. 2010; Debes et al. 2011). It will also provide crucial information on the IR sky at a sensitivity 100 times better than that of IRAS. However, the WISE team found an overestimate in brightness in the 4.6 μm (W 2) band6 and this bias reaches nearly 1 ma ...
... the Near-Earth Object population (Wright et al. 2010; Debes et al. 2011). It will also provide crucial information on the IR sky at a sensitivity 100 times better than that of IRAS. However, the WISE team found an overestimate in brightness in the 4.6 μm (W 2) band6 and this bias reaches nearly 1 ma ...
Discovery of Warm and Dense Molecular Gas Surrounding the Ring
... The search for molecular gas in these environments is still limited, possibly due to the a priori hypothesis by which the parent molecular cloud around an evolved massive star may have been destroyed soon after star formation. Even so, the detected lowexcitation CO (Marston et al. 1999; Nota et al. ...
... The search for molecular gas in these environments is still limited, possibly due to the a priori hypothesis by which the parent molecular cloud around an evolved massive star may have been destroyed soon after star formation. Even so, the detected lowexcitation CO (Marston et al. 1999; Nota et al. ...
Detecting Stars at the Galactic Centre via Synchrotron Emission
... ber of possible mechanisms have been proposed to account for the origin of the S-stars. Löckmann et al. (2008) argued that the dynamical interaction of two stellar disks in the central parsec could lead to the formation of the S-stars. Griv (2010) proposed that the S-stars were born in the disk and ...
... ber of possible mechanisms have been proposed to account for the origin of the S-stars. Löckmann et al. (2008) argued that the dynamical interaction of two stellar disks in the central parsec could lead to the formation of the S-stars. Griv (2010) proposed that the S-stars were born in the disk and ...
University of Groningen Photo-ionization studies of nebulae
... Abstract — A parameter study of the spectral evolution of a typical post-AGB star, with particular emphasis on the evolution of the infrared colors, is presented. The models are based on the latest evolutionary tracks for hydrogen burning post-AGB stars. For such tracks the evolutionary rate is very ...
... Abstract — A parameter study of the spectral evolution of a typical post-AGB star, with particular emphasis on the evolution of the infrared colors, is presented. The models are based on the latest evolutionary tracks for hydrogen burning post-AGB stars. For such tracks the evolutionary rate is very ...
The importance of episodic accretion for low
... Hubeny 1990). The gas is assumed to be a mixture of hydrogen (70%) and helium (30%) , with an equation of state (Black & Bodenheimer 1975) that accounts (i) for the rotational and vibrational degrees of freedom of molecular hydrogen, and (ii) for the different chemical states of hydrogen and helium. ...
... Hubeny 1990). The gas is assumed to be a mixture of hydrogen (70%) and helium (30%) , with an equation of state (Black & Bodenheimer 1975) that accounts (i) for the rotational and vibrational degrees of freedom of molecular hydrogen, and (ii) for the different chemical states of hydrogen and helium. ...
Understanding Mass-Loss and the Late Evolution of Intermediate
... abundances of the shock-superheated gas and allow us to associate it with the undiluted, nucleosynthesisenriched (C-rich) stellar wind. But such a study has been successfully done in only this one object due to the limited effective areas of CXO and XMM (300 ks yielded few×100 cts in the brightest l ...
... abundances of the shock-superheated gas and allow us to associate it with the undiluted, nucleosynthesisenriched (C-rich) stellar wind. But such a study has been successfully done in only this one object due to the limited effective areas of CXO and XMM (300 ks yielded few×100 cts in the brightest l ...
grains of
... tset with decreasing grain size (a) Micron-sized grains settle in about 105 years at 1 AU, although grains grow during their journey to the midplane => reduce the settling time-scale ...
... tset with decreasing grain size (a) Micron-sized grains settle in about 105 years at 1 AU, although grains grow during their journey to the midplane => reduce the settling time-scale ...
An Atlas of Stellar Spectra
... kinds: accurate color equivalents for many of the brighter stars and accurate absolute magnitudes for a number of the same stars. These results have been used to define the system of classification more precisely, both in the temperature equivalents and in the luminosity class. The most important of ...
... kinds: accurate color equivalents for many of the brighter stars and accurate absolute magnitudes for a number of the same stars. These results have been used to define the system of classification more precisely, both in the temperature equivalents and in the luminosity class. The most important of ...
Planets and Debris Disks: Results from a Spitzer/MIPS Search for IR
... are well established by radial-velocity measurements of the central star (e.g. Butler et al. 2006). For such systems, it is not clear what relationship to expect between planets and debris, since the dust responsible for the observed IR emission is generally well exterior to the radial-velocity plan ...
... are well established by radial-velocity measurements of the central star (e.g. Butler et al. 2006). For such systems, it is not clear what relationship to expect between planets and debris, since the dust responsible for the observed IR emission is generally well exterior to the radial-velocity plan ...
HST observations of the field star population in the Large Magellanic
... suggests an age for the younger population of slightly less than 1 Gyr, or of ~ 2 Gyr, depending on the adopted metallicity. The redder peak corresponds to a population with age ~2-4 Gyr, again depending on metallicity. Given the proximity of our field to the bar, we tentatively identify the younger ...
... suggests an age for the younger population of slightly less than 1 Gyr, or of ~ 2 Gyr, depending on the adopted metallicity. The redder peak corresponds to a population with age ~2-4 Gyr, again depending on metallicity. Given the proximity of our field to the bar, we tentatively identify the younger ...
pdf-file - Max-Planck-Institut für Astronomie
... and viscosity parameter α. The most essential finding is a very high temperature of the inner disk. For e.g., a 10 M protostar with an accretion rate of ∼10−4 M yr−1 , the disk midplane temperature may reach almost 105 K. The disk luminosity in this case is about 104 L and, thus, potentially high ...
... and viscosity parameter α. The most essential finding is a very high temperature of the inner disk. For e.g., a 10 M protostar with an accretion rate of ∼10−4 M yr−1 , the disk midplane temperature may reach almost 105 K. The disk luminosity in this case is about 104 L and, thus, potentially high ...
as a PDF - Research Database
... of luminosity and stellar effective temperature, Ṁ(L, T eff ), for oxygen-rich AGB stars and red supergiants in the LMC, which undergo strong regular pulsations (Whitelock et al. 2003) and are enshrouded in dusty envelopes. This is the first empirical relationship of its kind, that can be readily app ...
... of luminosity and stellar effective temperature, Ṁ(L, T eff ), for oxygen-rich AGB stars and red supergiants in the LMC, which undergo strong regular pulsations (Whitelock et al. 2003) and are enshrouded in dusty envelopes. This is the first empirical relationship of its kind, that can be readily app ...
ellc: A fast, flexible light curve model for detached eclipsing binary
... A = B = C = R and D = 0. This model can be very useful for rapidly calculating a large number of light curves and is accurate enough for many cases. The Roche potential is widely used to approximate stellar shapes in light curve models. I have used the definition of this potential described by Wilso ...
... A = B = C = R and D = 0. This model can be very useful for rapidly calculating a large number of light curves and is accurate enough for many cases. The Roche potential is widely used to approximate stellar shapes in light curve models. I have used the definition of this potential described by Wilso ...
The deep OB star population in Carina from the VST Photometric Hα
... Thaddeus 2001), the arm is traceable as a somewhat broken ridge of emission that has a near side about 2 kpc away, running from higher Galactic longitude to the tangent point 4–6 kpc distant (see the discussion by Dame 2007): it connects to the far side beyond the tangent as it carries on unwinding ...
... Thaddeus 2001), the arm is traceable as a somewhat broken ridge of emission that has a near side about 2 kpc away, running from higher Galactic longitude to the tangent point 4–6 kpc distant (see the discussion by Dame 2007): it connects to the far side beyond the tangent as it carries on unwinding ...
The white dwarf binary pathways survey – I. A sample of FGK stars
... the potential of this sample to test binary evolution models and type Ia supernovae formation channels. Key words: binaries: close – stars: white dwarfs – stars: early-type – stars: evolution ...
... the potential of this sample to test binary evolution models and type Ia supernovae formation channels. Key words: binaries: close – stars: white dwarfs – stars: early-type – stars: evolution ...
arXiv:1604.01613v2 [astro-ph.SR] 23 Aug 2016
... the potential of this sample to test binary evolution models and type Ia supernovae formation channels. Key words: binaries: close – stars: white dwarfs – stars: early-type – stars: evolution ...
... the potential of this sample to test binary evolution models and type Ia supernovae formation channels. Key words: binaries: close – stars: white dwarfs – stars: early-type – stars: evolution ...
NEAR-INFRARED THERMAL EMISSION FROM THE HOT JUPITER
... −0.011 % (5σ ). Our best-fit secondary eclipse is consistent with a circular orbit (a 3σ upper limit on the eccentricity, e, and argument or periastron, ω, of |e cos ω| < 0.0090), in agreement with mid-infrared detections of the secondary eclipse of this planet. A secondary eclipse of this depth cor ...
... −0.011 % (5σ ). Our best-fit secondary eclipse is consistent with a circular orbit (a 3σ upper limit on the eccentricity, e, and argument or periastron, ω, of |e cos ω| < 0.0090), in agreement with mid-infrared detections of the secondary eclipse of this planet. A secondary eclipse of this depth cor ...
STELLAR STRUCTURE AND EVOLUTION
... a star is an object that (1) radiates energy from an internal source and (2) is bound by its own gravity. This definition excludes objects like planets and comets, because they do not comply with the first criterion. In the strictest sense it also excludes brown dwarfs, which are not hot enough for ...
... a star is an object that (1) radiates energy from an internal source and (2) is bound by its own gravity. This definition excludes objects like planets and comets, because they do not comply with the first criterion. In the strictest sense it also excludes brown dwarfs, which are not hot enough for ...