The Korean 1592--1593 Record of a Guest Star: Animpostor`of the
... For example, SN 2009ip was a SN impostor from a LBV, and turned into a true SN three years later, which appeared as a SN IIn (Mauerhan et al. 2013). Could the guest star in 1592–1593 have been a SN impostor as a precursor of the Cas A SN as well? The time span of about 80 years between the appearanc ...
... For example, SN 2009ip was a SN impostor from a LBV, and turned into a true SN three years later, which appeared as a SN IIn (Mauerhan et al. 2013). Could the guest star in 1592–1593 have been a SN impostor as a precursor of the Cas A SN as well? The time span of about 80 years between the appearanc ...
StellarManual
... An incomplete sentence is presented that indicates the size and surface temperature a certain star has relative to the Sun. Students should determine how the stellar luminosity will compare with the Sun. Initially there is no equation displayed. Answer: Luminosity of a star is proportional to the sq ...
... An incomplete sentence is presented that indicates the size and surface temperature a certain star has relative to the Sun. Students should determine how the stellar luminosity will compare with the Sun. Initially there is no equation displayed. Answer: Luminosity of a star is proportional to the sq ...
The low-spin black hole in LMC X-3 Please share
... Leong et al. (1971) discovered LMC X-3 during the first year of the Uhuru mission. In 1983, Cowley et al. (1983) showed via dynamical observations that the compact X-ray source in this 1.7 day binary is a black hole (BH). In Orosz et al. (2014) we use new optical data to derive a much improved dynam ...
... Leong et al. (1971) discovered LMC X-3 during the first year of the Uhuru mission. In 1983, Cowley et al. (1983) showed via dynamical observations that the compact X-ray source in this 1.7 day binary is a black hole (BH). In Orosz et al. (2014) we use new optical data to derive a much improved dynam ...
High energy processes in young stellar objects and high-mass X
... 4.2 Fermi observational data . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3 Fermi /LAT data analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5 Discussion . . . . . . . . . . . . . . . ...
... 4.2 Fermi observational data . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3 Fermi /LAT data analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5 Discussion . . . . . . . . . . . . . . . ...
Feedback from winds and supernovae in massive stellar clusters – I
... Rosette nebula reveals that only a small proportion of the cluster wind energy is radiated in the X-ray, and Townsley et al. (2003) conclude that most of the hot gas must flow without cooling into the wider ISM. This picture is supported by the analysis of the Omega nebula, the Arches cluster and NG ...
... Rosette nebula reveals that only a small proportion of the cluster wind energy is radiated in the X-ray, and Townsley et al. (2003) conclude that most of the hot gas must flow without cooling into the wider ISM. This picture is supported by the analysis of the Omega nebula, the Arches cluster and NG ...
The incidence of stellar mergers and mass gainers among massive
... We assume that contact binaries merge. During the coalescence we assume in our standard simulations that a fraction µloss = 0.1 of the system mass is lost during the merger taking away the excess angular momentum. When investigating the uncertainties we consider the case that mass loss can be neglec ...
... We assume that contact binaries merge. During the coalescence we assume in our standard simulations that a fraction µloss = 0.1 of the system mass is lost during the merger taking away the excess angular momentum. When investigating the uncertainties we consider the case that mass loss can be neglec ...
Chapter 12 Pre-supernova evolution of massive stars
... Pre-supernova evolution of massive stars We have seen that low- and intermediate-mass stars (with masses up to ≈ 8 M⊙ ) develop carbonoxygen cores that become degenerate after central He burning. As a consequence the maximum core temperature reached in these stars is smaller than the temperature req ...
... Pre-supernova evolution of massive stars We have seen that low- and intermediate-mass stars (with masses up to ≈ 8 M⊙ ) develop carbonoxygen cores that become degenerate after central He burning. As a consequence the maximum core temperature reached in these stars is smaller than the temperature req ...
The Nuclear Equation of State and Neutron Star Masses
... neutron stars, such as radii and surface temperatures, can be estimated in a few cases from optical and X-ray observations of cooling neutron stars as well as from X-ray bursts and flares occurring on neutron star surfaces (see Section 4). One newly formed neutron star was observed in neutrinos (4) i ...
... neutron stars, such as radii and surface temperatures, can be estimated in a few cases from optical and X-ray observations of cooling neutron stars as well as from X-ray bursts and flares occurring on neutron star surfaces (see Section 4). One newly formed neutron star was observed in neutrinos (4) i ...
Note - HKU Physics
... of heavy elements. In astronomy, heavy elements (or some books call them by the misleading term “heavy metals”) are defined as elements with atomic number greater than 2. • Surface temperature: Ranges from about 4000 K to 30000 K for most main sequence stars. • Magnetic field strength: Of the order ...
... of heavy elements. In astronomy, heavy elements (or some books call them by the misleading term “heavy metals”) are defined as elements with atomic number greater than 2. • Surface temperature: Ranges from about 4000 K to 30000 K for most main sequence stars. • Magnetic field strength: Of the order ...
Swift and NuSTAR observations of XTE J1859+083
... seconds). Due to magnetic flux conservation during their birth, NS can have magnetic fields up to 1012 G. These fast rotation of the magnetic field and the strong magnetic field in general interacts with surrounding matter and produces high energetic photons. In the case of XTE J1859+083 it is expec ...
... seconds). Due to magnetic flux conservation during their birth, NS can have magnetic fields up to 1012 G. These fast rotation of the magnetic field and the strong magnetic field in general interacts with surrounding matter and produces high energetic photons. In the case of XTE J1859+083 it is expec ...
![Neutral material around the B[e] supergiant star LHA 115](http://s1.studyres.com/store/data/015508749_1-459b4c864ff7fdb1bc1eff2b9c6df4c4-300x300.png)
Neutral material around the B[e] supergiant star LHA 115
... the continuum, the Feii emission lines with a central absorption core, and many additional singly ionized metal lines (like those from Crii and Tiii, see Fig. 1) showing very narrow central absorption components which are nearly unshifted with respect to the emission component. For the typical B[e] ...
... the continuum, the Feii emission lines with a central absorption core, and many additional singly ionized metal lines (like those from Crii and Tiii, see Fig. 1) showing very narrow central absorption components which are nearly unshifted with respect to the emission component. For the typical B[e] ...
22 Years of a Pulsar
... • Inferred velocity: ~ 70 km/s (normal-ish for pulsars) • System origin thought to be in Cen OB1 association. • PM has it moving in correct direction ...
... • Inferred velocity: ~ 70 km/s (normal-ish for pulsars) • System origin thought to be in Cen OB1 association. • PM has it moving in correct direction ...
The hot-Jupiter Kepler-17b: discovery, obliquity from stroboscopic
... The astrometry derived from the Kepler images themselves, when combined with high-resolution images of the target neighborhood, provides a very powerful tool for identifying background eclipsing binaries blended with and contaminating the target images (Batalha et al. 2010). The astrometry of Kepler ...
... The astrometry derived from the Kepler images themselves, when combined with high-resolution images of the target neighborhood, provides a very powerful tool for identifying background eclipsing binaries blended with and contaminating the target images (Batalha et al. 2010). The astrometry of Kepler ...
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... Results. In contrast to historical expectations for sgB[e] stars, S18 is both photometrically and spectroscopically highly variable. The lightcurve is characterised by rapid aperiodic ‘flaring’ throughout the 16 years of observations. Changes in the high excitation emission line component of the spe ...
... Results. In contrast to historical expectations for sgB[e] stars, S18 is both photometrically and spectroscopically highly variable. The lightcurve is characterised by rapid aperiodic ‘flaring’ throughout the 16 years of observations. Changes in the high excitation emission line component of the spe ...
Jul y 9- 11,
... central supermassive black holes (SMBHs) will be more often present even in smaller galaxies when seeds are generated from the remnants of the first massive stars rather than via direct gas collapse. Consequently, measurement of the local occupation fraction provides an observational discriminator b ...
... central supermassive black holes (SMBHs) will be more often present even in smaller galaxies when seeds are generated from the remnants of the first massive stars rather than via direct gas collapse. Consequently, measurement of the local occupation fraction provides an observational discriminator b ...
What is a Black Hole?
... of mass at all can in principle be made to form a black hole if you compress it to a high enough density. We suspect that most of the black holes that are actually out there were produced in the deaths of massive stars, and so we expect those black holes to weigh about as much as a massive star. A t ...
... of mass at all can in principle be made to form a black hole if you compress it to a high enough density. We suspect that most of the black holes that are actually out there were produced in the deaths of massive stars, and so we expect those black holes to weigh about as much as a massive star. A t ...
Process of Science: PreMainSequence Stellar Life Tracks on the HR
... Notice that the rotation rate increases as the formation process progresses. This is a consequence of the law of conservation of angular momentum: The cloud inevitably starts with some small net rotation, so as it contracts (reducing the radius of the rotation) the rotation must speed up to keep the ...
... Notice that the rotation rate increases as the formation process progresses. This is a consequence of the law of conservation of angular momentum: The cloud inevitably starts with some small net rotation, so as it contracts (reducing the radius of the rotation) the rotation must speed up to keep the ...
X-ray Emission Line Profiles from ... Confined Wind Shock Model
... This model can simulate data that would be observed from a star with this wind structure. We now have the ability to obtain data with enough detail to allow fruitful comparison because of new instrumentation. The Chandra satellite has spectroscopic resolution capability that is better than the Einst ...
... This model can simulate data that would be observed from a star with this wind structure. We now have the ability to obtain data with enough detail to allow fruitful comparison because of new instrumentation. The Chandra satellite has spectroscopic resolution capability that is better than the Einst ...
The Circumstellar Environments of Young Stars at AU Scales
... measured NIR sizes are tightly contained within the sublimation radii of directly heated grey dust with sublimation temperatures of 1000 K−1500 K under the assumption that dust grains radiate over the full solid angle (e.g., no backwarming, solid lines in Fig. 2). If instead we assume that the dust ...
... measured NIR sizes are tightly contained within the sublimation radii of directly heated grey dust with sublimation temperatures of 1000 K−1500 K under the assumption that dust grains radiate over the full solid angle (e.g., no backwarming, solid lines in Fig. 2). If instead we assume that the dust ...
Cygnus X-1
Cygnus X-1 (abbreviated Cyg X-1) is a well-known galactic X-ray source, thought to be a black hole, in the constellation Cygnus. It was discovered in 1964 during a rocket flight and is one of the strongest X-ray sources seen from Earth, producing a peak X-ray flux density of 6977229999999999999♠2.3×10−23 Wm−2 Hz−1 (7003230000000000000♠2.3×103 Jansky). Cygnus X-1 was the first X-ray source widely accepted to be a black hole and it remains among the most studied astronomical objects in its class. The compact object is now estimated to have a mass about 14.8 times the mass of the Sun and has been shown to be too small to be any known kind of normal star, or other likely object besides a black hole. If so, the radius of its event horizon is about 7004440000000000000♠44 km.Cygnus X-1 belongs to a high-mass X-ray binary system about 7019574266339685654♠6070 ly from the Sun that includes a blue supergiant variable star designated HDE 226868 which it orbits at about 0.2 AU, or 20% of the distance from the Earth to the Sun. A stellar wind from the star provides material for an accretion disk around the X-ray source. Matter in the inner disk is heated to millions of degrees, generating the observed X-rays. A pair of jets, arranged perpendicular to the disk, are carrying part of the energy of the infalling material away into interstellar space.This system may belong to a stellar association called Cygnus OB3, which would mean that Cygnus X-1 is about five million years old and formed from a progenitor star that had more than 7001400000000000000♠40 solar masses. The majority of the star's mass was shed, most likely as a stellar wind. If this star had then exploded as a supernova, the resulting force would most likely have ejected the remnant from the system. Hence the star may have instead collapsed directly into a black hole.Cygnus X-1 was the subject of a friendly scientific wager between physicists Stephen Hawking and Kip Thorne in 1975, with Hawking betting that it was not a black hole. He conceded the bet in 1990 after observational data had strengthened the case that there was indeed a black hole in the system. This hypothesis has not been confirmed due to a lack of direct observation but has generally been accepted from indirect evidence.