The physics of star formation
... of their high opacity, the rate at which they are heated by external radiation is low; the result is that molecular clouds are very cold and have typical temperatures of only about 10–20 K. Higher temperatures of up to 100 K or more may exist locally in regions heated by luminous newly formed stars. ...
... of their high opacity, the rate at which they are heated by external radiation is low; the result is that molecular clouds are very cold and have typical temperatures of only about 10–20 K. Higher temperatures of up to 100 K or more may exist locally in regions heated by luminous newly formed stars. ...
GOMOS data characterisation and error estimation
... Fig. 6. Distribution of the mean occultation stopping altitude of 30 brightest stars in 2003–2006. ...
... Fig. 6. Distribution of the mean occultation stopping altitude of 30 brightest stars in 2003–2006. ...
Optical and Infrared Colors of Stars Observed by the
... 2000), and late-K and M stars are found at the red end of the stellar locus. Di†erent M spectral subtypes cannot be distinguished in the g*[r* versus u*[g* diagram, and these stars are better separated in the r*[i* versus g*[r* diagram. M stars have a constant g*[r* color (D1.4) due to strong TiO ba ...
... 2000), and late-K and M stars are found at the red end of the stellar locus. Di†erent M spectral subtypes cannot be distinguished in the g*[r* versus u*[g* diagram, and these stars are better separated in the r*[i* versus g*[r* diagram. M stars have a constant g*[r* color (D1.4) due to strong TiO ba ...
the article as PDF - Project VS
... The O-C diagram is a plot showing the observed times of maximum light (O) minus those calculated according to an adopted ephemeris (C) as a function of time. The horizontal axis of the an O-C diagram most often represent time, usually expressed in days. Scientists principally use the Julian Date (JD ...
... The O-C diagram is a plot showing the observed times of maximum light (O) minus those calculated according to an adopted ephemeris (C) as a function of time. The horizontal axis of the an O-C diagram most often represent time, usually expressed in days. Scientists principally use the Julian Date (JD ...
The physics of star formation
... Stars are the fundamental units of luminous matter in the universe, and they are responsible, directly or indirectly, for most of what we see when we observe it. They also serve as our primary tracers of the structure and evolution of the universe and its contents. Consequently, it is of central imp ...
... Stars are the fundamental units of luminous matter in the universe, and they are responsible, directly or indirectly, for most of what we see when we observe it. They also serve as our primary tracers of the structure and evolution of the universe and its contents. Consequently, it is of central imp ...
The physics of star formation - Yale Astronomy
... Stars are the fundamental units of luminous matter in the universe, and they are responsible, directly or indirectly, for most of what we see when we observe it. They also serve as our primary tracers of the structure and evolution of the universe and its contents. Consequently, it is of central imp ...
... Stars are the fundamental units of luminous matter in the universe, and they are responsible, directly or indirectly, for most of what we see when we observe it. They also serve as our primary tracers of the structure and evolution of the universe and its contents. Consequently, it is of central imp ...
MIXED CHEMISTRY
... using the Spitzer Space Telescope have found evidence for the complex carbon molecule in near and distant galaxies. The discoveries in space and the award of the Nobel Prize in physics this year for another carbon form, graphene, made the subject much more topical, he said. Huffman said it's enough ...
... using the Spitzer Space Telescope have found evidence for the complex carbon molecule in near and distant galaxies. The discoveries in space and the award of the Nobel Prize in physics this year for another carbon form, graphene, made the subject much more topical, he said. Huffman said it's enough ...
The local density of matter mapped by Hipparcos
... survey, be more luminous and hence younger and kinematically colder, which would narrow the velocity distribution. Finally, we are only measuring the part of the vertical velocity that comes from the proper motion in latitude. However, this is the smallest error of the three. From studies of the eff ...
... survey, be more luminous and hence younger and kinematically colder, which would narrow the velocity distribution. Finally, we are only measuring the part of the vertical velocity that comes from the proper motion in latitude. However, this is the smallest error of the three. From studies of the eff ...
Stellar Population Effects on the Inferred Photon Density at
... for the initial mass function (IMF) in our standard models, with a slope of -1.3 between 0.1 and 0.5 M and -2.35 at masses above this, extending to 100 M for the models used in this study. The shallow slope below a stellar mass of 0.5 M biases our models towards the more massive stellar populatio ...
... for the initial mass function (IMF) in our standard models, with a slope of -1.3 between 0.1 and 0.5 M and -2.35 at masses above this, extending to 100 M for the models used in this study. The shallow slope below a stellar mass of 0.5 M biases our models towards the more massive stellar populatio ...
Super and massive AGB stars-IV. Final fates
... Two main processes can reduce the core mass4 prior to the thermally pulsing phase, these being second dredge-up (2DU) and dredge-out. The occurrence of these events is crucial because they will largely dictate the subsequent evolution and fate of the star. If they are not efficient enough and the co ...
... Two main processes can reduce the core mass4 prior to the thermally pulsing phase, these being second dredge-up (2DU) and dredge-out. The occurrence of these events is crucial because they will largely dictate the subsequent evolution and fate of the star. If they are not efficient enough and the co ...
EXPLORING STELLAR EVOLUTION MODELS OF sdB STARS
... The stellar evolution calculations were done with version 7184 of MESA (Paxton et al. 2011, 2013) in order to extend the results of Østensen et al. (2012). MESA offers a variety of up-to-date physics modules, including several MLT convection options, and is capable of evolving stars through the He-fl ...
... The stellar evolution calculations were done with version 7184 of MESA (Paxton et al. 2011, 2013) in order to extend the results of Østensen et al. (2012). MESA offers a variety of up-to-date physics modules, including several MLT convection options, and is capable of evolving stars through the He-fl ...
Astronomy 112: The Physics of Stars Class 1 Notes
... example the transitions associated with the n = 1 state of hydrogen are in the ultraviolet, where the atmosphere is opaque, so these can only be measured by telescopes in space. Even from space, gas between the stars tends to strongly absorb these photons, so even if we could see these lines from in ...
... example the transitions associated with the n = 1 state of hydrogen are in the ultraviolet, where the atmosphere is opaque, so these can only be measured by telescopes in space. Even from space, gas between the stars tends to strongly absorb these photons, so even if we could see these lines from in ...
banff04
... Critical Macc at which all stellar UV photons are absorbed by in-falling matter plotted against spectral type (Walmsley 1995, Churchwell 2002): ...
... Critical Macc at which all stellar UV photons are absorbed by in-falling matter plotted against spectral type (Walmsley 1995, Churchwell 2002): ...
Sun, Stars and Planets Part 1: The Sun: its structure and energy
... • In thermodynamic equilibrium the overall properties of a physical system do not vary from point to point and do not change with time • But individual particles of the system are in motion and do have changing properties, eg electrons being removed from or attached to atoms • But there is a statist ...
... • In thermodynamic equilibrium the overall properties of a physical system do not vary from point to point and do not change with time • But individual particles of the system are in motion and do have changing properties, eg electrons being removed from or attached to atoms • But there is a statist ...
ongoing massive star formation in the bulge of m511 hjglm lamers,2
... bulge,ÏÏ and of 30 bright pointlike sources that we discovered in it. These point sources indicate ongoing star formation in the bulge region, which is otherwise dominated by old ([5 Gyr) stars (Paper I). The full HST -WFPC2 image of M51 is published in Paper I. The image shows that the nucleus is s ...
... bulge,ÏÏ and of 30 bright pointlike sources that we discovered in it. These point sources indicate ongoing star formation in the bulge region, which is otherwise dominated by old ([5 Gyr) stars (Paper I). The full HST -WFPC2 image of M51 is published in Paper I. The image shows that the nucleus is s ...
chemical compositions of rv tauri stars and related objects
... & Lambert (1990) noted the resemblance of the observed abundance pattern with that of the interstellar gas in which the metals are depleted through fractionation in the interstellar grains. Bond (1991) suggested that the extreme metal deficiency of HR 4049 like objects could be caused by the selecti ...
... & Lambert (1990) noted the resemblance of the observed abundance pattern with that of the interstellar gas in which the metals are depleted through fractionation in the interstellar grains. Bond (1991) suggested that the extreme metal deficiency of HR 4049 like objects could be caused by the selecti ...
Astronomy Astrophysics A VLT/FLAMES survey for massive binaries in Westerlund 1 &
... It might, however, be supposed that such line profile variability was the result of rotating global wind structures. Indeed, periodic spectral variability attributed to such a cause has previously been reported in the optical lines of the apparently single WRs WR1 & 6 (Morel et al. 1997; Chené & St- ...
... It might, however, be supposed that such line profile variability was the result of rotating global wind structures. Indeed, periodic spectral variability attributed to such a cause has previously been reported in the optical lines of the apparently single WRs WR1 & 6 (Morel et al. 1997; Chené & St- ...
mass transfer in close, rapidly accreting protobinaries
... specific entropy of the gas after it passes through the accretion shock, radiates and settles onto the surface, and is eventually buried in enough optical depth to prevent it from radiating further. A high accretion rate reduces the amount of time an accreted gas element has to radiate before it is ...
... specific entropy of the gas after it passes through the accretion shock, radiates and settles onto the surface, and is eventually buried in enough optical depth to prevent it from radiating further. A high accretion rate reduces the amount of time an accreted gas element has to radiate before it is ...
Giant molecular clouds: star factories
... tars are forming in our galaxy at a rate of between 1 and 4 solar masses of stars per year. In contrast to elliptical galaxies, which are largely devoid of star formation, star formation is still going on in spiral galaxies because of their reservoirs of molecular gas, the fuel for new stars. The di ...
... tars are forming in our galaxy at a rate of between 1 and 4 solar masses of stars per year. In contrast to elliptical galaxies, which are largely devoid of star formation, star formation is still going on in spiral galaxies because of their reservoirs of molecular gas, the fuel for new stars. The di ...
Carbon-enhanced metal-poor stars: the most pristine - HAL
... vertical direction, but are constant in the horizontal direction for any given depth; the atmosphere is supposed to be in hydrostatic equilibrium; all quantities are time independent; the stellar plasma is supposed to be in LTE, i.e. the particle velocities are given by a Maxwellian distribution at ...
... vertical direction, but are constant in the horizontal direction for any given depth; the atmosphere is supposed to be in hydrostatic equilibrium; all quantities are time independent; the stellar plasma is supposed to be in LTE, i.e. the particle velocities are given by a Maxwellian distribution at ...
Yellow supergiants as supernova progenitors: an indication of
... part of the HRD (see Sect. 1), we apply several prescriptions in this paper. We apply a multiplicative factor between three and ten to the standard mass-loss rate prescription described above, when the effective temperature of the star is lower than log(T eff /K) ≤ 3.8. The detailed list of the comput ...
... part of the HRD (see Sect. 1), we apply several prescriptions in this paper. We apply a multiplicative factor between three and ten to the standard mass-loss rate prescription described above, when the effective temperature of the star is lower than log(T eff /K) ≤ 3.8. The detailed list of the comput ...
Telescope Bernard Lyot/Narval The Observatory of Stellar Magnetism
... Program Magnetism in Massive Stars (MiMeS): origins and evolution of magnetic fields in hot stars, Herbig, OB Complex field on Tau Sco (Jardine et al.) ...
... Program Magnetism in Massive Stars (MiMeS): origins and evolution of magnetic fields in hot stars, Herbig, OB Complex field on Tau Sco (Jardine et al.) ...
Pre-main sequence stars, emission stars and recent star formation in
... in the Milky Way and is rich in massive early type stars concentrated in OB associations. The presence of nebulosity and massive stars indicate that the stars have been forming till very recently and the young clusters found here are the result of the recent star formation event. Though the above fa ...
... in the Milky Way and is rich in massive early type stars concentrated in OB associations. The presence of nebulosity and massive stars indicate that the stars have been forming till very recently and the young clusters found here are the result of the recent star formation event. Though the above fa ...
View/Open - NuSpace Home - National University of Science and
... From a dynamical gravitational view-point, consider a gravitationally bound system of matter. For such a system, the viral theorem applies and as first realized since the subject was first studied by Sir James Jeans (1929), a MC or portion thereof can collapse gravitationally under its one own weigh ...
... From a dynamical gravitational view-point, consider a gravitationally bound system of matter. For such a system, the viral theorem applies and as first realized since the subject was first studied by Sir James Jeans (1929), a MC or portion thereof can collapse gravitationally under its one own weigh ...
outer-disk populations in ngc 7793: evidence for stellar
... Key words: galaxies: evolution – galaxies: spiral – galaxies: stellar content – galaxies: structure – techniques: photometric Online-only material: color figures ...
... Key words: galaxies: evolution – galaxies: spiral – galaxies: stellar content – galaxies: structure – techniques: photometric Online-only material: color figures ...