Multiplicity in Early Stellar Evolution
... al., 2009) and the number of brown dwarfs formed (e.g., Bonnell et al., 2008; Bate, 2009a,b; Attwood et al., 2009). 3D HD SPH calculations by Bate (2009a) made predictions of the frequency of single, binary, triple and quadruple star systems formed during the collapse of a highly unstable cloud with ...
... al., 2009) and the number of brown dwarfs formed (e.g., Bonnell et al., 2008; Bate, 2009a,b; Attwood et al., 2009). 3D HD SPH calculations by Bate (2009a) made predictions of the frequency of single, binary, triple and quadruple star systems formed during the collapse of a highly unstable cloud with ...
Lightning climatology of exoplanets and brown dwarfs guided by
... lightning climatology for the different atmospheric environments of Earth, Venus, Jupiter and Saturn. We present lightning distribution maps for Earth, Jupiter and Saturn, and flash densities for these planets and Venus, based on optical and/or radio measurements from the World Wide Lightning Locati ...
... lightning climatology for the different atmospheric environments of Earth, Venus, Jupiter and Saturn. We present lightning distribution maps for Earth, Jupiter and Saturn, and flash densities for these planets and Venus, based on optical and/or radio measurements from the World Wide Lightning Locati ...
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... dusty circumstellar disk around Beta Pictoris (β Pic), a nearby and seemingly normal main sequence star hotter and more massive than the Sun (spectral type A5V). For more than a decade, this system has been under intense scrutiny because of its suspected similarity to either a forming or a young pla ...
... dusty circumstellar disk around Beta Pictoris (β Pic), a nearby and seemingly normal main sequence star hotter and more massive than the Sun (spectral type A5V). For more than a decade, this system has been under intense scrutiny because of its suspected similarity to either a forming or a young pla ...
A new method to determine the mean density of massive Solar
... Oberon; Person et al. (2006) – Neptune’s satellite Triton. Thus and so, the present article analysis includes data on the known mean densities of 131 objects of the Solar System. The article treats a body’s mean density as a principal and self-sufficient, rather than subsidiary, characteristic of th ...
... Oberon; Person et al. (2006) – Neptune’s satellite Triton. Thus and so, the present article analysis includes data on the known mean densities of 131 objects of the Solar System. The article treats a body’s mean density as a principal and self-sufficient, rather than subsidiary, characteristic of th ...
Reassessing the formation of the inner Oort cloud
... either a Hernquist or Plummer potential – and chose other parameters based on the latest observations of embedded clusters from the literature. These other parameters result in the stars being on radial orbits and the cluster collapses. Similar to previous studies, in our simulations the inner Oort ...
... either a Hernquist or Plummer potential – and chose other parameters based on the latest observations of embedded clusters from the literature. These other parameters result in the stars being on radial orbits and the cluster collapses. Similar to previous studies, in our simulations the inner Oort ...
Intelligent Life in the Universe - e
... Recent advances in search techniques for planets, in the theory of planet formation, and particularly in biochemistry, molecular, and cell biology are about to give answers to these questions: how life appeared and how many planets can be expected in the universe on which life, and eventually intell ...
... Recent advances in search techniques for planets, in the theory of planet formation, and particularly in biochemistry, molecular, and cell biology are about to give answers to these questions: how life appeared and how many planets can be expected in the universe on which life, and eventually intell ...
A New Science Strategy for Space Astronomy and Astrophysics
... In 1991 the National Research Council issued a detailed strategy for astronomy and astrophysics for the next decade,1 prepared by a committee under the leadership of John Bahcall. Like previous decadal studies in this field, the report identified in priority order the most important scientific progr ...
... In 1991 the National Research Council issued a detailed strategy for astronomy and astrophysics for the next decade,1 prepared by a committee under the leadership of John Bahcall. Like previous decadal studies in this field, the report identified in priority order the most important scientific progr ...
gerard peter kuiper - National Academy of Sciences
... least in outline; that it was identical to the general process of star formation, from slightly turbulent prestellar clouds upon contraction, with conservation of angular momentum. It followed that the Solar System was no more than an "unsuccessful" double star with the companion mass spread out rad ...
... least in outline; that it was identical to the general process of star formation, from slightly turbulent prestellar clouds upon contraction, with conservation of angular momentum. It followed that the Solar System was no more than an "unsuccessful" double star with the companion mass spread out rad ...
The physics of star formation
... structure of these small star-forming clouds; the dust is the best readily observable tracer of the mass distribution because most of the heavier molecules freeze out onto the dust grains at high densities. Many of these small clouds are dense enough for ...
... structure of these small star-forming clouds; the dust is the best readily observable tracer of the mass distribution because most of the heavier molecules freeze out onto the dust grains at high densities. Many of these small clouds are dense enough for ...
The chemical composition of solar-type stars and its impact on the
... a roundup of the achievements in this field and a theoretical outlook on the next years, see, e.g., S. Seager (2011, [153]). Planet search is usually conducted using two different methods, the radial velocity method and the transit one. In the radial velocity method, displacements of a star’s spectr ...
... a roundup of the achievements in this field and a theoretical outlook on the next years, see, e.g., S. Seager (2011, [153]). Planet search is usually conducted using two different methods, the radial velocity method and the transit one. In the radial velocity method, displacements of a star’s spectr ...
The physics of star formation
... high luminosities for their temperatures indicate that they are extremely young and have ages of typically only about 1 Myr (Herbig 1962, Cohen and Kuhi 1979). These T Tauri stars are the youngest known visible stars, and they are ‘pre-main-sequence’ stars that have not yet become ...
... high luminosities for their temperatures indicate that they are extremely young and have ages of typically only about 1 Myr (Herbig 1962, Cohen and Kuhi 1979). These T Tauri stars are the youngest known visible stars, and they are ‘pre-main-sequence’ stars that have not yet become ...
The physics of star formation - Yale Astronomy
... high luminosities for their temperatures indicate that they are extremely young and have ages of typically only about 1 Myr (Herbig 1962, Cohen and Kuhi 1979). These T Tauri stars are the youngest known visible stars, and they are ‘pre-main-sequence’ stars that have not yet become ...
... high luminosities for their temperatures indicate that they are extremely young and have ages of typically only about 1 Myr (Herbig 1962, Cohen and Kuhi 1979). These T Tauri stars are the youngest known visible stars, and they are ‘pre-main-sequence’ stars that have not yet become ...
Barium and europium abundances in cool dwarf stars and
... halo stars are of the r-process origin. Much observational efforts were invested in testing this idea. For extremely metalpoor stars with metallicities [Fe/H] ≤ −2.4 McWilliam (1998) has derived an average [Eu/Ba] = 0.69, consistent with pure rprocess nucleosynthesis provided that the data of Arland ...
... halo stars are of the r-process origin. Much observational efforts were invested in testing this idea. For extremely metalpoor stars with metallicities [Fe/H] ≤ −2.4 McWilliam (1998) has derived an average [Eu/Ba] = 0.69, consistent with pure rprocess nucleosynthesis provided that the data of Arland ...
ASTRONOMY AND ASTROPHYSICS Barium and europium
... halo stars are of the r-process origin. Much observational efforts were invested in testing this idea. For extremely metalpoor stars with metallicities [Fe/H] ≤ −2.4 McWilliam (1998) has derived an average [Eu/Ba] = 0.69, consistent with pure rprocess nucleosynthesis provided that the data of Arland ...
... halo stars are of the r-process origin. Much observational efforts were invested in testing this idea. For extremely metalpoor stars with metallicities [Fe/H] ≤ −2.4 McWilliam (1998) has derived an average [Eu/Ba] = 0.69, consistent with pure rprocess nucleosynthesis provided that the data of Arland ...
The science case for - Astrophysics
... dominated by poorly understood dark matter and a mysterious vacuum energy density. This progress poses new, and more fundamental, questions, the answers to some of which will perhaps unite astrophysics with elementary particle physics in a new approach to the nature of matter. Some discoveries, made ...
... dominated by poorly understood dark matter and a mysterious vacuum energy density. This progress poses new, and more fundamental, questions, the answers to some of which will perhaps unite astrophysics with elementary particle physics in a new approach to the nature of matter. Some discoveries, made ...
Hunting for Substructure in the Milky Way
... In previous years, astronomers had a simple outlook on the structure of our Galaxy, which has evolved over time with ongoing research in the area. At its most basic level, the Milky Way is a barred disk galaxy with spiral arms. Its main components are the central bulge, the disk and the surrounding ...
... In previous years, astronomers had a simple outlook on the structure of our Galaxy, which has evolved over time with ongoing research in the area. At its most basic level, the Milky Way is a barred disk galaxy with spiral arms. Its main components are the central bulge, the disk and the surrounding ...
1998 - Universitäts-Sternwarte München
... strictly differential with respect to the Sun. The modeling of the spectral lines is based on T. Gehren’s (1975) atmosphere program that makes use of the standard assumptions such as hydrostatic equilibrium, plane-parallel layers and local thermodynamic equilibrium, and is fed by the opacity distrib ...
... strictly differential with respect to the Sun. The modeling of the spectral lines is based on T. Gehren’s (1975) atmosphere program that makes use of the standard assumptions such as hydrostatic equilibrium, plane-parallel layers and local thermodynamic equilibrium, and is fed by the opacity distrib ...
Analysis of Stellar Activity and Orbital Dynamics in Extrasolar
... hosting an active star are particularly interesting if the planet transits the stellar disk, because in this case the planet allows to spatially resolve activity-related photospheric, chromospheric and coronal features in the host star’s atmosphere. This work is dedicated to the study of orbital dyn ...
... hosting an active star are particularly interesting if the planet transits the stellar disk, because in this case the planet allows to spatially resolve activity-related photospheric, chromospheric and coronal features in the host star’s atmosphere. This work is dedicated to the study of orbital dyn ...
9 The Clearing of Protoplanetary Disks and of the Protosolar Nebula
... 9.1.2 Constraints on the dispersal of the gas component The initial mass and lifetime of gas in circumstellar disks affect both the formation of giant planets as well as the formation of terrestrial planets. According to the widely accepted scenario of giant planet formation, rocky cores need to rea ...
... 9.1.2 Constraints on the dispersal of the gas component The initial mass and lifetime of gas in circumstellar disks affect both the formation of giant planets as well as the formation of terrestrial planets. According to the widely accepted scenario of giant planet formation, rocky cores need to rea ...
Conference Abstract Booklet here.
... component analysis methods. The theoretical Cepheid light curves are obtained using the full amplitude, nonlinear, convective hydrodynamical models for chemical compositions relative to Cepheids in the Galaxy (Y=0.28, Z=0.02), Large Magellanic Cloud (Y=0.25, Z=0.008) and Small Magellanic Cloud (Y=0. ...
... component analysis methods. The theoretical Cepheid light curves are obtained using the full amplitude, nonlinear, convective hydrodynamical models for chemical compositions relative to Cepheids in the Galaxy (Y=0.28, Z=0.02), Large Magellanic Cloud (Y=0.25, Z=0.008) and Small Magellanic Cloud (Y=0. ...
swiss ephemeris - Welcome, but
... 5.1.1. Introduction ......................................................................................................................................... 30 5.1.2. Aspect determining visibility ...................................................................................................... ...
... 5.1.1. Introduction ......................................................................................................................................... 30 5.1.2. Aspect determining visibility ...................................................................................................... ...
Lokal fulltext - Chalmers Publication Library
... Just a month later the same year, Smith & Terrile (1984) published their observations of β Pictoris. They announced that they had been able to observe optically a circumstellar disc around the star. They infer that they have detected an edge-on disc of ∼ 400 AU in radius (see Figure 1.2). They did n ...
... Just a month later the same year, Smith & Terrile (1984) published their observations of β Pictoris. They announced that they had been able to observe optically a circumstellar disc around the star. They infer that they have detected an edge-on disc of ∼ 400 AU in radius (see Figure 1.2). They did n ...
Magnetic cycles of Sun-like stars with different levels of coronal and
... The most sensitive indicator of the chromospheric activity (CA) is the Mount Wilson S - index (SHK ) - the ratio of the core of the CaII H&K lines to the nearby continuum (Vaugan & Preston 1980). Now the CaII H&K emission was established as the main indicator of CA in lower main sequence stars. The ...
... The most sensitive indicator of the chromospheric activity (CA) is the Mount Wilson S - index (SHK ) - the ratio of the core of the CaII H&K lines to the nearby continuum (Vaugan & Preston 1980). Now the CaII H&K emission was established as the main indicator of CA in lower main sequence stars. The ...
Chemical composition of 90 F and G disk dwarfs
... flat-field correction, order extraction and wavelength calibration. Bias, dark current and scattered light corrections are included in the background subtraction. If an early B-type star could be observed close to the program stars, it was used instead of the flat-field in order to remove interferen ...
... flat-field correction, order extraction and wavelength calibration. Bias, dark current and scattered light corrections are included in the background subtraction. If an early B-type star could be observed close to the program stars, it was used instead of the flat-field in order to remove interferen ...
Planetary system
A planetary system is a set of gravitationally bound non-stellar objects in orbit around a star or star system. Generally speaking, systems with one or more planets constitute a planetary system, although such systems may also consist of bodies such as dwarf planets, asteroids, natural satellites, meteoroids, comets, planetesimals and circumstellar disks. The Sun together with its planetary system, which includes Earth, is known as the Solar System. The term exoplanetary system is sometimes used in reference to other planetary systems.A total of 1968 exoplanets (in 1248 planetary systems, including 490 multiple planetary systems) have been identified as of 1 October 2015.Of particular interest to astrobiology is the habitable zone of planetary systems where planets could have surface liquid water.