Lecture 12: Evolution of the Galaxy
... ASTR112 The Galaxy Lecture 12 • The Galaxy is presumed to have started from a huge extended low density cloud of H and He • This underwent rapid gravitational collapse over ~2 × 108 years (halo era) during which time the Population II stars were formed, all with low metallicity • As collapse procee ...
... ASTR112 The Galaxy Lecture 12 • The Galaxy is presumed to have started from a huge extended low density cloud of H and He • This underwent rapid gravitational collapse over ~2 × 108 years (halo era) during which time the Population II stars were formed, all with low metallicity • As collapse procee ...
As far as - Sangeeta Malhotra
... performed spectroscopy on the HUDF target region between October 2002 and January 2003, using about 10 percent of the time that went into imaging. We quickly discovered that GRAPES is not just an extragalactic survey, for the HUDF distance scale starts within our own galaxy. The closest object we ha ...
... performed spectroscopy on the HUDF target region between October 2002 and January 2003, using about 10 percent of the time that went into imaging. We quickly discovered that GRAPES is not just an extragalactic survey, for the HUDF distance scale starts within our own galaxy. The closest object we ha ...
Title: Binary interaction dominates the evolution of massive stars
... CCSNe predominantly result from mass transfer in close binaries. This rate is large enough to explain the discrepancy between the large observational fraction of Type Ib/c supernovae and the dearth of single stars stripped by stellar winds. Our results also imply that more than half of the progenito ...
... CCSNe predominantly result from mass transfer in close binaries. This rate is large enough to explain the discrepancy between the large observational fraction of Type Ib/c supernovae and the dearth of single stars stripped by stellar winds. Our results also imply that more than half of the progenito ...
Article PDF - IOPscience
... astronomical systems also emit solid particles, which could yield valuable information if detected. The dust detectors on the Ulysses and Galileo spacecraft have yielded preliminary information on the flux of interstellar grains passing through the solar system (Frisch et al. 1999; Landgraf et al. 2 ...
... astronomical systems also emit solid particles, which could yield valuable information if detected. The dust detectors on the Ulysses and Galileo spacecraft have yielded preliminary information on the flux of interstellar grains passing through the solar system (Frisch et al. 1999; Landgraf et al. 2 ...
The Stability of Exomoons in the Habitable Zone
... conditions must then be upheld for quite some time to allow potential life to arise, meaning the orbit of the body must be fairly stable. In this investigation, all the objects at exoplanets.org (as of 2014-04-29) were evaluated to see which of these that could possibly have habitable moons, taking ...
... conditions must then be upheld for quite some time to allow potential life to arise, meaning the orbit of the body must be fairly stable. In this investigation, all the objects at exoplanets.org (as of 2014-04-29) were evaluated to see which of these that could possibly have habitable moons, taking ...
Variability of solar/stellar activity and magnetic field and its influence... planetary atmosphere evolution
... and expansion of the upper atmosphere and should have played an important role for large-scale atmospheric escape and isotopic fractionation on early Venus, Earth, and Mars. Because lower-mass stars are very common and hence may host rocky planets within their habitable zones, progress in this direc ...
... and expansion of the upper atmosphere and should have played an important role for large-scale atmospheric escape and isotopic fractionation on early Venus, Earth, and Mars. Because lower-mass stars are very common and hence may host rocky planets within their habitable zones, progress in this direc ...
UK Exoplanet community meeting 2017
... Discussion and Q&A: Stellar Activity in Exoplanet Surveys – Dr Heather Cegla and Dr Raphaëlle Haywood – The main obstacle that we currently face in the detection and characterisation of small planets comes from the intrinsic variability of the host stars themselves. The UK hosts world-leading exper ...
... Discussion and Q&A: Stellar Activity in Exoplanet Surveys – Dr Heather Cegla and Dr Raphaëlle Haywood – The main obstacle that we currently face in the detection and characterisation of small planets comes from the intrinsic variability of the host stars themselves. The UK hosts world-leading exper ...
The Astrophysical Origins of the Short
... 5. Temperatures inside magnetosphere at least 750 K, and usually > 1200 K [Shu et al. (1996)]. Chlorine (including 36Cl) requires T < 970 K to condense [Lodders (2003)] 6. Many other SLRs cannot be produced by spallation, including 60Fe, 107Pd and 182Hf [Gounelle et al. (2001); Leya et al. (2003)] ...
... 5. Temperatures inside magnetosphere at least 750 K, and usually > 1200 K [Shu et al. (1996)]. Chlorine (including 36Cl) requires T < 970 K to condense [Lodders (2003)] 6. Many other SLRs cannot be produced by spallation, including 60Fe, 107Pd and 182Hf [Gounelle et al. (2001); Leya et al. (2003)] ...
Physics of Star Formation: Milky Way and Beyond
... this structure affect their production of stars? This paper presents new models of axisymmetric star-forming filaments having no cores, one low-mass core, and one cluster-forming core. The models resemble observed clouds in their column density maps and radial profiles, and their N-pdf distributions ...
... this structure affect their production of stars? This paper presents new models of axisymmetric star-forming filaments having no cores, one low-mass core, and one cluster-forming core. The models resemble observed clouds in their column density maps and radial profiles, and their N-pdf distributions ...
Celestial Globes Armillary Spheres
... equatorial rings and constellation outlines. Instead, Al-Battānī had a more precise method of charting the stars using the ecliptic and equator, and dividing them in to small divisions (fig.3). This method then allowed the stars to be given exact coordinates, and thus increased precision7. The Musli ...
... equatorial rings and constellation outlines. Instead, Al-Battānī had a more precise method of charting the stars using the ecliptic and equator, and dividing them in to small divisions (fig.3). This method then allowed the stars to be given exact coordinates, and thus increased precision7. The Musli ...
1. Uranus and Neptune
... He began what was an enormous task. He made photographs of sections of the sky under conditions that would pick up stars as dim as magnitude 13. Such a photograph might contain hundreds of thousands of stars. He would then take another photograph of the same part of the sky a few days later. All the ...
... He began what was an enormous task. He made photographs of sections of the sky under conditions that would pick up stars as dim as magnitude 13. Such a photograph might contain hundreds of thousands of stars. He would then take another photograph of the same part of the sky a few days later. All the ...
Planetary system formation in thermally evolving viscous
... with h = 0.1 were also performed. Eccentricities in the range 0 ≤ e ≤ 0.3 were considered. Figure 1a shows the time-averaged surface density perturbation for the h = 0.07 disc with mp = 5 M⊕ for different eccentricities. Thermal relaxation and viscosity were optimized to prevent entropy/vortensity c ...
... with h = 0.1 were also performed. Eccentricities in the range 0 ≤ e ≤ 0.3 were considered. Figure 1a shows the time-averaged surface density perturbation for the h = 0.07 disc with mp = 5 M⊕ for different eccentricities. Thermal relaxation and viscosity were optimized to prevent entropy/vortensity c ...
CHEOPS Science Requirements Document
... far from the Sun. This has been explained by the fact that, in order to grow large fast enough, these bodies require ices in condensed form, which are only available in cold and hence distant regions of the protoplanetary disc. Contrariwise, most detected giant exoplanets are located in regions much ...
... far from the Sun. This has been explained by the fact that, in order to grow large fast enough, these bodies require ices in condensed form, which are only available in cold and hence distant regions of the protoplanetary disc. Contrariwise, most detected giant exoplanets are located in regions much ...
Abundances and possible diffusion of elements in M 67 stars⋆
... and (parametrised) additional mixing of unknown origin. Similar effects, albeit of smaller overall amplitude, have recently been traced in NGC 6752 at somewhat higher metallicities (Gruyters et al. 2013). In M 4, at roughly one tenth solar metallicity, no abundance trend in iron was found between the ...
... and (parametrised) additional mixing of unknown origin. Similar effects, albeit of smaller overall amplitude, have recently been traced in NGC 6752 at somewhat higher metallicities (Gruyters et al. 2013). In M 4, at roughly one tenth solar metallicity, no abundance trend in iron was found between the ...
Stargazing For Beginners: A Binocular Tour of the Southern Night Sky
... nebulae, and star clusters. It assumes you are equipped with nothing more than a simple pair of binoculars, and that you know nothing of astronomy or the layout of the night sky. The course is inspired by the 19th century book entitled Astronomy with an Opera Glass by Garrett Serviss, but has been c ...
... nebulae, and star clusters. It assumes you are equipped with nothing more than a simple pair of binoculars, and that you know nothing of astronomy or the layout of the night sky. The course is inspired by the 19th century book entitled Astronomy with an Opera Glass by Garrett Serviss, but has been c ...
W. M. White Geochemistry Chapter 10: Cosmochemistry
... we learn about the evolution of the Earth by examining old rocks, we can learn about the evolution of the cosmos by looking at old stars. The old stars of Population II are considerably poorer in heavy elements than are young stars. In particular, Population II stars have a Fe/H ratio typically a fa ...
... we learn about the evolution of the Earth by examining old rocks, we can learn about the evolution of the cosmos by looking at old stars. The old stars of Population II are considerably poorer in heavy elements than are young stars. In particular, Population II stars have a Fe/H ratio typically a fa ...
Flatfielding chapter for Calibration Volumes
... We can expect each chip to have slightly different overall quantum efficiency due to variations in the manufacturing process, especially if devices are taken from different lots. As a star moves from one detector of a given sort to another, its observed magnitude will therefore jump by some small am ...
... We can expect each chip to have slightly different overall quantum efficiency due to variations in the manufacturing process, especially if devices are taken from different lots. As a star moves from one detector of a given sort to another, its observed magnitude will therefore jump by some small am ...
Aquarius (constellation)
Aquarius is a constellation of the zodiac, situated between Capricornus and Pisces. Its name is Latin for ""water-carrier"" or ""cup-carrier"", and its symbol is 20px (Unicode ♒), a representation of water.Aquarius is one of the oldest of the recognized constellations along the zodiac (the sun's apparent path). It was one of the 48 constellations listed by the 2nd century AD astronomer Ptolemy, and it remains one of the 88 modern constellations. It is found in a region often called the Sea due to its profusion of constellations with watery associations such as Cetus the whale, Pisces the fish, and Eridanus the river.