Asteroseismic Modelling of Solar-like Stars
... are highly determined by the global stellar properties and the inner structure of the stars, asteroseimology is a perfect tool to test our current understanding of stars. With the acquisition of high quality oscillation data, the theories of stellar structure and evolution and theories of stellar pu ...
... are highly determined by the global stellar properties and the inner structure of the stars, asteroseimology is a perfect tool to test our current understanding of stars. With the acquisition of high quality oscillation data, the theories of stellar structure and evolution and theories of stellar pu ...
The nature of the faint galaxies in the Hubble Deep Field
... by mergers (67 per cent of the mergers in Fig. 1 have B - V < 0.5) and cover a range of U - B colours ( - 1 < U - B < 1), locating them at different redshifts. These are reasonably well fitted by our galaxy models, shifted to high redshifts (z'" 1.5-3). According to these models, most of the mergers ...
... by mergers (67 per cent of the mergers in Fig. 1 have B - V < 0.5) and cover a range of U - B colours ( - 1 < U - B < 1), locating them at different redshifts. These are reasonably well fitted by our galaxy models, shifted to high redshifts (z'" 1.5-3). According to these models, most of the mergers ...
Gaia 1 and 2. A pair of new satellites of the Galaxy
... Gaia-detected sources is indeed very prominent (top left and top middle panels). Note a white patch corresponding to a dearth of Gaia sources near the centre of the over-density. This is the location of Sirius, where Gaia struggles to detect genuine stars3 . The area affected by Sirius is much large ...
... Gaia-detected sources is indeed very prominent (top left and top middle panels). Note a white patch corresponding to a dearth of Gaia sources near the centre of the over-density. This is the location of Sirius, where Gaia struggles to detect genuine stars3 . The area affected by Sirius is much large ...
Stellar Wind Mechanisms and Instabilities
... roughly (i.e. within an order unity factor 3) the ratio between the gas internal energy and the gravitational escape energy. For the solar photosphere, s∗ ≈ 2.2 × 10−4 , and even for very hot stars with an order of magnitude higher photospheric temperature, this parameter is still quite small, s∗ ∼ ...
... roughly (i.e. within an order unity factor 3) the ratio between the gas internal energy and the gravitational escape energy. For the solar photosphere, s∗ ≈ 2.2 × 10−4 , and even for very hot stars with an order of magnitude higher photospheric temperature, this parameter is still quite small, s∗ ∼ ...
CENTRAL STARS OF PLANETARY NEBULAE IN THE LARGE
... run on the combined file, with the motivation being that more total counts for both the target and background allow for a better extraction. However, this method did not result in a significant improvement over the others. The adopted background model for each star is indicated in Table 1. The resul ...
... run on the combined file, with the motivation being that more total counts for both the target and background allow for a better extraction. However, this method did not result in a significant improvement over the others. The adopted background model for each star is indicated in Table 1. The resul ...
Constraints on the physical properties and chemical evolution of star
... about both the nature of these stars and the physical conditions in the interstellar medium. In particular, prominent emission lines produced by H ii regions, diffuse ionized gas and a potential active galactic nucleus in a galaxy are routinely used as global diagnostics of gas metallicity and excit ...
... about both the nature of these stars and the physical conditions in the interstellar medium. In particular, prominent emission lines produced by H ii regions, diffuse ionized gas and a potential active galactic nucleus in a galaxy are routinely used as global diagnostics of gas metallicity and excit ...
3011800000630
... UV band, but also contributes to the total optical emission. The extension of the same irradiation model to outer regions of the disk explains the IR radiation. The disk luminosity is dominated by the contribution of irradiation at outer radii where the thermal radiation peaks in the longer waveleng ...
... UV band, but also contributes to the total optical emission. The extension of the same irradiation model to outer regions of the disk explains the IR radiation. The disk luminosity is dominated by the contribution of irradiation at outer radii where the thermal radiation peaks in the longer waveleng ...
Differential rotation of main sequence F stars
... most rigid rotation law. Note also that for fast rotation all lines are practically horizontal, i.e. there is no radial shear, while the model with a rotation period of 27 d shows a substantial decrease of the rotation rate with increasing radius at high latitudes. This change of the rotation patter ...
... most rigid rotation law. Note also that for fast rotation all lines are practically horizontal, i.e. there is no radial shear, while the model with a rotation period of 27 d shows a substantial decrease of the rotation rate with increasing radius at high latitudes. This change of the rotation patter ...
Hint of a transiting extended atmosphere on 55 Cancri b⋆
... The naked-eye star 55 Cancri hosts a planetary system with five known planets, including a hot super-Earth (55 Cnc e) extremely close to its star and a farther out giant planet (55 Cnc b), found in milder irradiation conditions with respect to other known hot Jupiters. This system raises important q ...
... The naked-eye star 55 Cancri hosts a planetary system with five known planets, including a hot super-Earth (55 Cnc e) extremely close to its star and a farther out giant planet (55 Cnc b), found in milder irradiation conditions with respect to other known hot Jupiters. This system raises important q ...
Full Text
... Het begint al bij de keuze van het type gerecht. Je laat je leiden door je eigen smaak, maar ook het enthousiasme van anderen kan je al op voorhand doen watertanden. Christoffel, hierin speelde je een uitermate belangrijke rol. Het enthousiasme waarmee je de lessen inleiding tot de sterrenkunde op d ...
... Het begint al bij de keuze van het type gerecht. Je laat je leiden door je eigen smaak, maar ook het enthousiasme van anderen kan je al op voorhand doen watertanden. Christoffel, hierin speelde je een uitermate belangrijke rol. Het enthousiasme waarmee je de lessen inleiding tot de sterrenkunde op d ...
About the Instructor`s Guide
... lead author changed his graduate study plans from biophysics to astrophysics as a result of watching the series.) Thus, while the series does not correspond directly to the textbook, it makes an outstanding resource for reinforcing key ideas. There are at least two basic ways in which you can use th ...
... lead author changed his graduate study plans from biophysics to astrophysics as a result of watching the series.) Thus, while the series does not correspond directly to the textbook, it makes an outstanding resource for reinforcing key ideas. There are at least two basic ways in which you can use th ...
Fundamental properties of Ana González Galán
... The aim of this thesis is to characterise a sample of High Mass X-ray Binaries (HMXBs) formed by: IGR J00370+6122, XTE J1855-026, AX J1841.0-0535 and AX J1845.0-0433. These objects are composed of pulsars (rotating neutron stars) accreting material from the wind of their supergiant companions. The X ...
... The aim of this thesis is to characterise a sample of High Mass X-ray Binaries (HMXBs) formed by: IGR J00370+6122, XTE J1855-026, AX J1841.0-0535 and AX J1845.0-0433. These objects are composed of pulsars (rotating neutron stars) accreting material from the wind of their supergiant companions. The X ...
Abd al-Rahman al-Sufi and his book of the fixed stars: a journey of
... translating the main sections of this book. The other objective was to try and point out the importance of this author and this book in the history of astronomy. I found that al-Ṣūfī’s ...
... translating the main sections of this book. The other objective was to try and point out the importance of this author and this book in the history of astronomy. I found that al-Ṣūfī’s ...
Progenitor systems of Type Ia Supernovae: mergers of white dwarfs
... cal mechanism behind the explosion. There is, however, general agreement that type Ib/Ic and type II supernovae share the same explosion mechanism and that it is fundamentally different from the explosion mechanism of type Ia supernovae. The former are associated with the death of massive stars ( M ...
... cal mechanism behind the explosion. There is, however, general agreement that type Ib/Ic and type II supernovae share the same explosion mechanism and that it is fundamentally different from the explosion mechanism of type Ia supernovae. The former are associated with the death of massive stars ( M ...
WTS-1 b: the fi rst extrasolar planet detected in the WFCAM Transit
... Statue of Giordano Bruno . . . . . . . . . . . . . . . . . . . . . . Detection methods: radial velocity and transit . . . . . . . . . . . Detection methods: gravitational microlensing and astrometry . . T-Tauri star . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Snow line . . . . . . . ...
... Statue of Giordano Bruno . . . . . . . . . . . . . . . . . . . . . . Detection methods: radial velocity and transit . . . . . . . . . . . Detection methods: gravitational microlensing and astrometry . . T-Tauri star . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Snow line . . . . . . . ...
Differential rotation on both components of the pre-main
... The first technique that was employed to measure stellar differential rotation using Doppler imaging involved cross-correlating image maps. This was done for the early differential rotation measurements on the K0-dwarf AB Dor by Donati & Collier Cameron (1997) and Donati et al. (1999). The technique ...
... The first technique that was employed to measure stellar differential rotation using Doppler imaging involved cross-correlating image maps. This was done for the early differential rotation measurements on the K0-dwarf AB Dor by Donati & Collier Cameron (1997) and Donati et al. (1999). The technique ...
Star formation
Star formation is the process by which dense regions within molecular clouds in interstellar space, sometimes referred to as ""stellar nurseries"" or ""star-forming regions"", collapse to form stars. As a branch of astronomy, star formation includes the study of the interstellar medium (ISM) and giant molecular clouds (GMC) as precursors to the star formation process, and the study of protostars and young stellar objects as its immediate products. It is closely related to planet formation, another branch of astronomy. Star formation theory, as well as accounting for the formation of a single star, must also account for the statistics of binary stars and the initial mass function.In June 2015, astronomers reported evidence for Population III stars in the Cosmos Redshift 7 galaxy at z = 6.60. Such stars are likely to have existed in the very early universe (i.e., at high redshift), and may have started the production of chemical elements heavier than hydrogen that are needed for the later formation of planets and life as we know it.