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... We used to think massive cluster formation to be a thing of the past (the Globular Clusters). First, we began to see evidence of very massive clusters (proto-globular clusters) forming in other galaxies ...
... We used to think massive cluster formation to be a thing of the past (the Globular Clusters). First, we began to see evidence of very massive clusters (proto-globular clusters) forming in other galaxies ...
WASP-42 b and WASP-49 b: two new transiting sub
... to planets of the mass of Jupiter (e.g. HAT-P-32 b, Hartman et al. 2011). The most striking examples are WASP-17 b having a density of ρ = 0.06 ρJ (Anderson et al. 2010, 2011) and Kepler-12 b with a density of ρ = 0.09 ρJ (Fortney et al. 2011). It appears that there is a mechanism depositing energy ...
... to planets of the mass of Jupiter (e.g. HAT-P-32 b, Hartman et al. 2011). The most striking examples are WASP-17 b having a density of ρ = 0.06 ρJ (Anderson et al. 2010, 2011) and Kepler-12 b with a density of ρ = 0.09 ρJ (Fortney et al. 2011). It appears that there is a mechanism depositing energy ...
Models of protosolar nebula evolution The
... momentum is in the Outer Planets orbits, and only a tiny fraction in the Sun itself (despite it holding more than 99.8% of the mass). The mechanism invoked to exchange angular momentum determines the kind of nebula evolution. For instance, in massive (very young) disks, gravitational instabilities c ...
... momentum is in the Outer Planets orbits, and only a tiny fraction in the Sun itself (despite it holding more than 99.8% of the mass). The mechanism invoked to exchange angular momentum determines the kind of nebula evolution. For instance, in massive (very young) disks, gravitational instabilities c ...
Study Systematics on the ICM metallicity measurements
... and Observations 1:1 •Simulations are now very powerful: large cosmological boxes are simulated with sophisticated physics. ...
... and Observations 1:1 •Simulations are now very powerful: large cosmological boxes are simulated with sophisticated physics. ...
Determining the Stellar Spin Axis Orientation
... Recent interferometric observations have managed to determine the spin axis orientation for a handful of early-type fast-rotating stars (Monnier et al (2007) and deSouza et al (2003)). Indeed, fast rotating stars are theorized to present cases of gravitation-darkening, i.e. the equatorial latitude o ...
... Recent interferometric observations have managed to determine the spin axis orientation for a handful of early-type fast-rotating stars (Monnier et al (2007) and deSouza et al (2003)). Indeed, fast rotating stars are theorized to present cases of gravitation-darkening, i.e. the equatorial latitude o ...
Read more - University of Central Lancashire
... I don’t know. We are discovering a lot of new planets using the Kepler Space Telescope and if we find a planet that is just like Earth then we might find life there. I think there are too many planets out there for there not to be life, we just haven’t discovered it yet. When will the sun explode? T ...
... I don’t know. We are discovering a lot of new planets using the Kepler Space Telescope and if we find a planet that is just like Earth then we might find life there. I think there are too many planets out there for there not to be life, we just haven’t discovered it yet. When will the sun explode? T ...
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... Required for most stars with Te < 10000 K, corresponds to convective instability => Microturbulence ~ convection, at least in cooler stars Detectable even in broad-line stars – much data ...
... Required for most stars with Te < 10000 K, corresponds to convective instability => Microturbulence ~ convection, at least in cooler stars Detectable even in broad-line stars – much data ...
RESEARCH STATEMENT Chromospheres and winds
... the International Ultraviolet Explorer (IUE) [3]. ζ Aurigae has been observed at the Dominion Astronomical Observatory (DAO) over many eclipse cycles with the 1.2 m telescope. The chromospheric Ca ii K absorption line in high resolution spectra taken using the McKellar spectrograph have sometimes be ...
... the International Ultraviolet Explorer (IUE) [3]. ζ Aurigae has been observed at the Dominion Astronomical Observatory (DAO) over many eclipse cycles with the 1.2 m telescope. The chromospheric Ca ii K absorption line in high resolution spectra taken using the McKellar spectrograph have sometimes be ...
FIRST LIGHT IN THE UNIVERSE
... Myr with large dust opacity (sub-mm galaxy overlap) • Superwinds drive out both gas and dust, resulting in more quiescent star formation (10’s M yr-1) and smaller UV extinction • Quiescent star formation phase lasts for at least a few hundred Myr; by end at least a few 1010 M of stars have formed ...
... Myr with large dust opacity (sub-mm galaxy overlap) • Superwinds drive out both gas and dust, resulting in more quiescent star formation (10’s M yr-1) and smaller UV extinction • Quiescent star formation phase lasts for at least a few hundred Myr; by end at least a few 1010 M of stars have formed ...
Galaxy Formation,! Reionization, ! the First Stars and Quasars! Ay 127!
... • The smallest scale density fluctuations keep collapsing, with baryons falling into the potential wells dominated by the dark matter, achieving high densties through cooling! – This process starts right after the recombination at z ~ 1100! ...
... • The smallest scale density fluctuations keep collapsing, with baryons falling into the potential wells dominated by the dark matter, achieving high densties through cooling! – This process starts right after the recombination at z ~ 1100! ...
Formation and composition of planets around very low mass stars
... the planetary mass: planets that do not contain a lot of water are generally of lower mass (below ∼ 1M⊕ , although some can be as massive as ∼ 1.5M⊕ ), and planets totally devoid of water are all less massive than 1M⊕ , and even lower than 0.4M⊕ if one does not consider the massive disks. This can b ...
... the planetary mass: planets that do not contain a lot of water are generally of lower mass (below ∼ 1M⊕ , although some can be as massive as ∼ 1.5M⊕ ), and planets totally devoid of water are all less massive than 1M⊕ , and even lower than 0.4M⊕ if one does not consider the massive disks. This can b ...
February 2004
... Mars is still in the evening sky in the north west, perhaps almost forgotten after its showing last August, it could be mistaken for a star like Betelgeuse, (it nearly was!) but it is still in a part of the sky where there are not many other bright objects. It showed a small disc in Michael’s 3 inch ...
... Mars is still in the evening sky in the north west, perhaps almost forgotten after its showing last August, it could be mistaken for a star like Betelgeuse, (it nearly was!) but it is still in a part of the sky where there are not many other bright objects. It showed a small disc in Michael’s 3 inch ...
ppt
... A sinusoidal light curve means orbits are close to circular From analysis of light curve it is possible to determine the eccentricity and orbit orientation, but not the inclination. In practice most orbits are circular because tidal interactions between the stars tend to circularize the orbits ...
... A sinusoidal light curve means orbits are close to circular From analysis of light curve it is possible to determine the eccentricity and orbit orientation, but not the inclination. In practice most orbits are circular because tidal interactions between the stars tend to circularize the orbits ...
stars - Chandra X
... coronal activity depends on Teff, not mass! * Old BDs: X-ray faint – but not radio faint! Magnetic activity persists, but coronal heating ...
... coronal activity depends on Teff, not mass! * Old BDs: X-ray faint – but not radio faint! Magnetic activity persists, but coronal heating ...
When Extrasolar Planets Transit Their Parent Stars
... depths and durations that resemble planetary ones (Brown, 2003), and this effect is especially pronounced for candidate transits having depths greater than 1%. (For equal-sized components, roughly 20% of eclipsing systems have eclipse depths that are less than 2% of the total light.) In these cases ...
... depths and durations that resemble planetary ones (Brown, 2003), and this effect is especially pronounced for candidate transits having depths greater than 1%. (For equal-sized components, roughly 20% of eclipsing systems have eclipse depths that are less than 2% of the total light.) In these cases ...
Using Python to Study Rotational Velocity Distributions of Hot Stars
... rotation up to 400 km/s. By definition, a star is born when it starts synthesizing Hydrogen into Helium through nuclear fusion. The star performs this nucleosynthesis during some 90% of their life. When stars are at this stage, they are called dwarfs. Most of the studied stars on this work are dwarf ...
... rotation up to 400 km/s. By definition, a star is born when it starts synthesizing Hydrogen into Helium through nuclear fusion. The star performs this nucleosynthesis during some 90% of their life. When stars are at this stage, they are called dwarfs. Most of the studied stars on this work are dwarf ...
Lithium production by thermohaline mixing in low
... Spite plateau value. It is therefore possible that low-mass AGB stars have contributed to the Galaxy’s Li budget. The effect of a population of low-mass, low-metallicity lithium producers on Galactic chemical evolution models should be investigated. These models do improve the agreement of the AGB m ...
... Spite plateau value. It is therefore possible that low-mass AGB stars have contributed to the Galaxy’s Li budget. The effect of a population of low-mass, low-metallicity lithium producers on Galactic chemical evolution models should be investigated. These models do improve the agreement of the AGB m ...
MIXED CHEMISTRY
... Now, 25 years after the discovery, Huffman is excited that astronomers 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, ...
... Now, 25 years after the discovery, Huffman is excited that astronomers 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, ...
TOWARD A MODEL FOR THE Be BINARY SYSTEM PER 1
... spectrum. Therefore, unless greatly underluminous or the primary overluminous by some three magnitudes, the late type star should be visible in the infrared spectrum of Persei if it exists.
Evidence of the late-type secondary can also be searched for at still longer
wavelengths from 2.3 to 19.5 ...
... spectrum. Therefore, unless greatly underluminous or the primary overluminous by some three magnitudes, the late type star should be visible in the infrared spectrum of
Constraining planet structure from stellar chemistry: the cases of
... used a LTE analysis relative to the Sun with the 2014 version of the code MOOG (Sneden 1973) and a grid of Kurucz ATLAS9 plane-parallel model atmospheres with no α-enhancement. For the EW measurements, we used ARES2 (Sousa et al. 2015), for which the input parameters were the same as in Sousa et al. ...
... used a LTE analysis relative to the Sun with the 2014 version of the code MOOG (Sneden 1973) and a grid of Kurucz ATLAS9 plane-parallel model atmospheres with no α-enhancement. For the EW measurements, we used ARES2 (Sousa et al. 2015), for which the input parameters were the same as in Sousa et al. ...
TWO NEW VARIABLE STARS OBSERVED IN THE FIELD OF THE
... Our opinion is that the latter hypothesis is much more reliable and it is based on the following clues. In Table 3 we report the V, J, H and K magnitudes for this object as given by the GSC2.3 and 2MASS catalogues. The V-K color index for this target is higher than expected for a G-type star, while ...
... Our opinion is that the latter hypothesis is much more reliable and it is based on the following clues. In Table 3 we report the V, J, H and K magnitudes for this object as given by the GSC2.3 and 2MASS catalogues. The V-K color index for this target is higher than expected for a G-type star, while ...
Potential biosignatures in super
... emission curves according to effective temperatures and stellar parameters as specified in Kaltenegger & Traub (2009, see Table 1). But these input spectra neglect that many M-dwarf stars show strong activity in the UV range, much more than our Sun, for example. The high UV radiation can have a signi ...
... emission curves according to effective temperatures and stellar parameters as specified in Kaltenegger & Traub (2009, see Table 1). But these input spectra neglect that many M-dwarf stars show strong activity in the UV range, much more than our Sun, for example. The high UV radiation can have a signi ...
Kepler-210: An active star with at least two planets⋆
... e and φt it is thus possible to to constrain the range of permissible eccentricities as well as values for φt , for which the derived stellar density becomes equal to the density expected for the spectral type of the star for both planets; the corresponding curves are shown in Fig. 7, where we plot ...
... e and φt it is thus possible to to constrain the range of permissible eccentricities as well as values for φt , for which the derived stellar density becomes equal to the density expected for the spectral type of the star for both planets; the corresponding curves are shown in Fig. 7, where we plot ...
Astronomy Astrophysics MY Camelopardalis, a very massive merger progenitor &
... Mergers are the consequence of angular momentum loss in tidally synchronised systems with short initial orbital periods (Andronov et al. 2006). The physics of mergers is poorly understood, but it is believed that they follow a common envelope phase. This phase, when both stars share the same envelop ...
... Mergers are the consequence of angular momentum loss in tidally synchronised systems with short initial orbital periods (Andronov et al. 2006). The physics of mergers is poorly understood, but it is believed that they follow a common envelope phase. This phase, when both stars share the same envelop ...
The Central Star Candidate of the Planetary Nebula Sh2
... and also indicated periodic sharp brightness dips, possibly eclipses, with a period of 17.2 days. In addition, the comparison between U and V lightcurves revealed that the 68-day brightness variations are accompanied by a variable reddening effect of ∆E(U − V ) = 0.38. Spectroscopic datasets demonst ...
... and also indicated periodic sharp brightness dips, possibly eclipses, with a period of 17.2 days. In addition, the comparison between U and V lightcurves revealed that the 68-day brightness variations are accompanied by a variable reddening effect of ∆E(U − V ) = 0.38. Spectroscopic datasets demonst ...
Planetary nebula
A planetary nebula, often abbreviated as PN or plural PNe, is a kind of emission nebula consisting of an expanding glowing shell of ionized gas ejected from old red giant stars late in their lives. The word ""nebula"" is Latin for mist or cloud and the term ""planetary nebula"" is a misnomer that originated in the 1780s with astronomer William Herschel because when viewed through his telescope, these objects appeared to him to resemble the rounded shapes of planets. Herschel's name for these objects was popularly adopted and has not been changed. They are a relatively short-lived phenomenon, lasting a few tens of thousands of years, compared to a typical stellar lifetime of several billion years.A mechanism for formation of most planetary nebulae is thought to be the following: at the end of the star's life, during the red giant phase, the outer layers of the star are expelled by strong stellar winds. Eventually, after most of the red giant's atmosphere is dissipated, the exposed hot, luminous core emits ultraviolet radiation to ionize the ejected outer layers of the star. Absorbed ultraviolet light energises the shell of nebulous gas around the central star, appearing as a bright coloured planetary nebula at several discrete visible wavelengths.Planetary nebulae may play a crucial role in the chemical evolution of the Milky Way, returning material to the interstellar medium from stars where elements, the products of nucleosynthesis (such as carbon, nitrogen, oxygen and neon), have been created. Planetary nebulae are also observed in more distant galaxies, yielding useful information about their chemical abundances.In recent years, Hubble Space Telescope images have revealed many planetary nebulae to have extremely complex and varied morphologies. About one-fifth are roughly spherical, but the majority are not spherically symmetric. The mechanisms which produce such a wide variety of shapes and features are not yet well understood, but binary central stars, stellar winds and magnetic fields may play a role.