Epsilon Aurigae: a rare stellar eclipse - Project VS
... silhouette of the disc beginning to move across the surface of the primary star. The size of the disc was measured at about 2.4 billion kilometers across, which is almost two times larger of the orbit of Jupiter. Though disk's mass was estimated to be ~ 0.1 that of Earth. It is enough for the disc t ...
... silhouette of the disc beginning to move across the surface of the primary star. The size of the disc was measured at about 2.4 billion kilometers across, which is almost two times larger of the orbit of Jupiter. Though disk's mass was estimated to be ~ 0.1 that of Earth. It is enough for the disc t ...
The Kuiper Belt and Other Debris Disks - UCLA
... typically large (Figure 1), suggesting a gravitationally bound, spheroidal source region of order 100,000 AU in extent (Oort 1950). Comets in the cloud are scattered randomly into the planetary region by the action of passing stars and also perturbed by the asymmetric gravitational potential of the ...
... typically large (Figure 1), suggesting a gravitationally bound, spheroidal source region of order 100,000 AU in extent (Oort 1950). Comets in the cloud are scattered randomly into the planetary region by the action of passing stars and also perturbed by the asymmetric gravitational potential of the ...
Doppler spectroscopy as a path to the detection of Earth
... At the beginning of the 1990s, two different approaches were used to determine precise stellar radial velocities. On the one hand, spectrographs with absorption cells in the beam of the spectrograph (hydrogen-fluoride cell or iodine cell)14,15, and on the other hand, fibre-fed spectrographs with sim ...
... At the beginning of the 1990s, two different approaches were used to determine precise stellar radial velocities. On the one hand, spectrographs with absorption cells in the beam of the spectrograph (hydrogen-fluoride cell or iodine cell)14,15, and on the other hand, fibre-fed spectrographs with sim ...
Extra-solar planets - Centro de Astrofísica da Universidade do Porto
... The growing number of exoplanets is now allowing statistical analysis of their properties (e.g., Udry et al., 2003), as well as of their host stars (Gonzalez, 1998; Santos et al., 2004c). These studies are providing the first constraints on the physical and chemical processes involved in the formatio ...
... The growing number of exoplanets is now allowing statistical analysis of their properties (e.g., Udry et al., 2003), as well as of their host stars (Gonzalez, 1998; Santos et al., 2004c). These studies are providing the first constraints on the physical and chemical processes involved in the formatio ...
Galactic planetary science
... around every type of stars from A to M, including pulsars and binaries. Being the leftover of the stellar formation processes, planets appear to be rather ubiquitous and, in reality, the presence of a host star is not even a mandatory circumstance. The current statistical estimates indicate that, on ...
... around every type of stars from A to M, including pulsars and binaries. Being the leftover of the stellar formation processes, planets appear to be rather ubiquitous and, in reality, the presence of a host star is not even a mandatory circumstance. The current statistical estimates indicate that, on ...
Extra-solar planets: detection methods and results
... As for the astrometric technique, the RV method has its own limitations. It is well known that intrinsic stellar features, like non-radial pulsation, inhomogeneous convection, or spots may be responsible for the detection of radialvelocity variations (Brown et al., 1998; Saar and Donahue, 1997; Sant ...
... As for the astrometric technique, the RV method has its own limitations. It is well known that intrinsic stellar features, like non-radial pulsation, inhomogeneous convection, or spots may be responsible for the detection of radialvelocity variations (Brown et al., 1998; Saar and Donahue, 1997; Sant ...
Systems of Multiple Planets
... thereafter. Intense monitoring (especially by D.A.F. during the past four years) reveals a minimum in the velocity residuals, indicating closure of the outer orbit (see Fig. 4 and Marcy et al., 2002). A two–planet fit to 55 Cancri leaves residuals that exhibit a periodicity of 44 days, possibly caus ...
... thereafter. Intense monitoring (especially by D.A.F. during the past four years) reveals a minimum in the velocity residuals, indicating closure of the outer orbit (see Fig. 4 and Marcy et al., 2002). A two–planet fit to 55 Cancri leaves residuals that exhibit a periodicity of 44 days, possibly caus ...
Presolar Cloud Collapse and the Formation and Early Evolution of
... roughly the 1/2 power, as is predicted to be the case if ambipolar diffusion controls the cloud’s dynamics (Mouschovias, 1991). Ambipolar diffusion is the process of slippage of the primarily neutral gas molecules past the ions, to which the magnetic field lines are effectively attached. This proces ...
... roughly the 1/2 power, as is predicted to be the case if ambipolar diffusion controls the cloud’s dynamics (Mouschovias, 1991). Ambipolar diffusion is the process of slippage of the primarily neutral gas molecules past the ions, to which the magnetic field lines are effectively attached. This proces ...
DUSTY CIRCUMSTELLAR DISKS B. Zuckerman
... It has not been easy to find old T Tauri stars, in the 10- to 20-million-year range, because such stars are hard to identify with IR and optical techniques. Recently, surveys of X-ray emission, especially with the German ROSAT satellite, have enabled detection of many stars that appear to be old or ...
... It has not been easy to find old T Tauri stars, in the 10- to 20-million-year range, because such stars are hard to identify with IR and optical techniques. Recently, surveys of X-ray emission, especially with the German ROSAT satellite, have enabled detection of many stars that appear to be old or ...
PYTS/ASTR 206 – Extrasolar Planets
... We can detect Jupiter-like planet but not Earth-like planets ...
... We can detect Jupiter-like planet but not Earth-like planets ...
Astronomy Astrophysics The HARPS search for southern extra-solar planets &
... fairly regularly spaced on a logarithmic scale, giving rise to approximate Titius-Bode-like (i.e. exponential) laws. These dynamical architectures can be interpreted as the signature of formation scenarios where type I migration and interactions between protoplanets play a major role. However, it re ...
... fairly regularly spaced on a logarithmic scale, giving rise to approximate Titius-Bode-like (i.e. exponential) laws. These dynamical architectures can be interpreted as the signature of formation scenarios where type I migration and interactions between protoplanets play a major role. However, it re ...
SPATIAL STUDY WITH THE VERY LARGE TELESCOPE OF A NEW
... (VLT) under 0>4 seeing conditions, which unveil a dark dust lane oriented east-west between two characteristic northern and southern reflection nebulae. This new circumstellar dust disk has a radius of 2>15 (300 AU at 140 pc) and a width of 1>2 (170 AU at 140 pc). Thanks to its location at the periph ...
... (VLT) under 0>4 seeing conditions, which unveil a dark dust lane oriented east-west between two characteristic northern and southern reflection nebulae. This new circumstellar dust disk has a radius of 2>15 (300 AU at 140 pc) and a width of 1>2 (170 AU at 140 pc). Thanks to its location at the periph ...
Extrasolar Planet Orbits and Eccentricities
... One of the remarkable features of extrasolar planets is their large eccentricities: the median eccentricity of 0.28 is larger than the maximum eccentricity of any planet in the solar system. The eccentricity distribution of extrasolar planets differs from that of solar system planets at the 99.9% KS ...
... One of the remarkable features of extrasolar planets is their large eccentricities: the median eccentricity of 0.28 is larger than the maximum eccentricity of any planet in the solar system. The eccentricity distribution of extrasolar planets differs from that of solar system planets at the 99.9% KS ...
Nazwy gwiazd nieba północnego o etymologii arabskiej
... wyszczególnieniem osób, które wniosły najwięcej. Wykreślone są również etapy transferu nazw arabskich do języków europejskich. Kolejny rozdział to kompilacja nazw gwiazd o etymologii arabskiej z gwiazdozbiorów półkuli północnej. Pogrupowane zostały one alfabetycznie według łacińskich nazw gwiazdozbi ...
... wyszczególnieniem osób, które wniosły najwięcej. Wykreślone są również etapy transferu nazw arabskich do języków europejskich. Kolejny rozdział to kompilacja nazw gwiazd o etymologii arabskiej z gwiazdozbiorów półkuli północnej. Pogrupowane zostały one alfabetycznie według łacińskich nazw gwiazdozbi ...
Towards a Classification System of Terrestrial Planets
... Existing ways to obtain information on the composition of an extrasolar planet are limited. In rare cases when the planetary orbit is seen edge on from the Earth, transit photometry and radial velocity measurements yield the radius, mass and hence the density of the planet, from which rough estimate ...
... Existing ways to obtain information on the composition of an extrasolar planet are limited. In rare cases when the planetary orbit is seen edge on from the Earth, transit photometry and radial velocity measurements yield the radius, mass and hence the density of the planet, from which rough estimate ...
AAVSO: Epsilon Aurigae
... Most recent interpretations of the observations seem to confirm the model set forth in 1991. It is now likely that there is an early-type binary system with components having spectral class B5 or earlier at the center of the disk, based upon the ultraviolet spectrum obtained with FUSE (Bennett et al ...
... Most recent interpretations of the observations seem to confirm the model set forth in 1991. It is now likely that there is an early-type binary system with components having spectral class B5 or earlier at the center of the disk, based upon the ultraviolet spectrum obtained with FUSE (Bennett et al ...
The Milky Way thin disk structure as revealed by stars and young
... when seen face-off, possess dusty and gaseous disks where stars are barely visible. On the other hand, when seen face-on, they exhibit quite spectacular structures in the form of gaseous and stellar spiral arms, bridges, inter-arm structures, knots, bifurcations, and so forth. These detailed shapes a ...
... when seen face-off, possess dusty and gaseous disks where stars are barely visible. On the other hand, when seen face-on, they exhibit quite spectacular structures in the form of gaseous and stellar spiral arms, bridges, inter-arm structures, knots, bifurcations, and so forth. These detailed shapes a ...
Bez nadpisu
... to the luminosity of the system than afterward, when it is exhausted. The heights of the maxima in the pre-outburst state are different because we view the region where the stream and the outer parts of the disk interact from different angles. On the other hand, the depths of the minima are differen ...
... to the luminosity of the system than afterward, when it is exhausted. The heights of the maxima in the pre-outburst state are different because we view the region where the stream and the outer parts of the disk interact from different angles. On the other hand, the depths of the minima are differen ...
REVIEW - Department of Astrophysical Sciences
... and gravity). This ratio can be ~0.1 to 0.01, correspondingly making it more difficult to determine a transit radius spectrum. Only telescopes such as the Spitzer Space Telescope9, the Hubble Space Telescope and the largest ground-based telescopes with advanced spectrometers are up to the task, and ...
... and gravity). This ratio can be ~0.1 to 0.01, correspondingly making it more difficult to determine a transit radius spectrum. Only telescopes such as the Spitzer Space Telescope9, the Hubble Space Telescope and the largest ground-based telescopes with advanced spectrometers are up to the task, and ...
Looking for planets with SPHERE in planetary systems with double
... systems, in which planets have formed- or failed to form- a long time ago. It is inferred that these planetesimals orbit their host star at asteroid to Kuiper belt distances and continually supply fresh dust through mutual collisions. The main aim of this work is to analyze systems that own a debris ...
... systems, in which planets have formed- or failed to form- a long time ago. It is inferred that these planetesimals orbit their host star at asteroid to Kuiper belt distances and continually supply fresh dust through mutual collisions. The main aim of this work is to analyze systems that own a debris ...
The Milky Way disk
... the third quadrant. On the opposite, in (Churchwell et al., 2009) the Local arm appears as a truncated normal arm, floating in between and almost parallel to the Carina-Sagittarius and Perseus arms. Such view is supported by the recent maser study by (Xu et al., 2013). These authors used maser data ...
... the third quadrant. On the opposite, in (Churchwell et al., 2009) the Local arm appears as a truncated normal arm, floating in between and almost parallel to the Carina-Sagittarius and Perseus arms. Such view is supported by the recent maser study by (Xu et al., 2013). These authors used maser data ...
Planet Formation: Disk Formation and Evolution
... In terms of the composition and bulk chemistry, we find the smaller rocky planets (Mercury, Venus, Earth, Mars) in the inner part of the Solar System, while the larger gas/ice giants (Jupiter, Saturn, Uranus, Neptune) reside farther out. The density of the planets decreases with heliocentric distanc ...
... In terms of the composition and bulk chemistry, we find the smaller rocky planets (Mercury, Venus, Earth, Mars) in the inner part of the Solar System, while the larger gas/ice giants (Jupiter, Saturn, Uranus, Neptune) reside farther out. The density of the planets decreases with heliocentric distanc ...
Planet formation around stars of various masses: The snow line and
... MMSN disk around a solar-mass star. There are several motivating factors for extending these theories to a range of stellar masses: (i) the increasing stellar mass range of extra-solar planet hosts, (ii) observed trends with stellar mass, such as accretion rate and disk mass, and (iii) theoretical r ...
... MMSN disk around a solar-mass star. There are several motivating factors for extending these theories to a range of stellar masses: (i) the increasing stellar mass range of extra-solar planet hosts, (ii) observed trends with stellar mass, such as accretion rate and disk mass, and (iii) theoretical r ...
ph507-16-1exo3
... 1) The mass distribution rises toward the lowest detectable masses, dN/dM ~ M -1.0. 2) Stellar metallicity associted with jupiter-sized planets correlates strongly with the presence of planets. Sample exhibits a planet-metallicity correlation at all stellar masses; this argues that the high metallic ...
... 1) The mass distribution rises toward the lowest detectable masses, dN/dM ~ M -1.0. 2) Stellar metallicity associted with jupiter-sized planets correlates strongly with the presence of planets. Sample exhibits a planet-metallicity correlation at all stellar masses; this argues that the high metallic ...
Beta Pictoris
Beta Pictoris (β Pic, β Pictoris) is the second brightest star in the constellation Pictor. It is located 63.4 light years from our solar system, and is 1.75 times as massive and 8.7 times as luminous as the Sun. The Beta Pictoris system is very young, only 8–20 million years old, although it is already in the main sequence stage of its evolution. Beta Pictoris is the title member of the Beta Pictoris moving group, an association of young stars which share the same motion through space and have the same age.Beta Pictoris shows an excess of infrared emission compared to normal stars of its type, which is caused by large quantities of dust and gas (including carbon monoxide) near the star. Detailed observations reveal a large disk of dust and gas orbiting the star, which was the first debris disk to be imaged around another star. In addition to the presence of several planetesimal belts and cometary activity, there are indications that planets have formed within this disk and that the processes of planet formation may still be ongoing. Material from the Beta Pictoris debris disk is thought to be the dominant source of interstellar meteoroids in our solar system.The European Southern Observatory (ESO) has confirmed the presence of a planet, Beta Pictoris b, matching previous predictions, through the use of direct imagery, orbiting in the plane of the debris disk surrounding the star. This planet is currently the closest extrasolar planet to its star ever photographed: the observed separation is roughly the same as the distance between Saturn and the Sun.