Colloquial Jakartan Indonesian
... changing positions on their flat maps by using compass, sextant, chronometer, almanacs and various mathematical tables. When Europeans first ventured into the Pacific they had to grapple with the almost inconceivable notion that Pacific Islanders could navigate their canoes successfully over distanc ...
... changing positions on their flat maps by using compass, sextant, chronometer, almanacs and various mathematical tables. When Europeans first ventured into the Pacific they had to grapple with the almost inconceivable notion that Pacific Islanders could navigate their canoes successfully over distanc ...
Sparse aperture masking at the VLT II. Detection limits for the eight
... 3.80 µm, ∆λ = 0.62 µm) using two of the four masks available on NaCo, the "Broad Band (BB) 9 holes" and the "7 holes" masks. Observational details such as mask used, integration time (DIT), size of datacube, and number of exposures for each science target are summarized in Table 1. The operational m ...
... 3.80 µm, ∆λ = 0.62 µm) using two of the four masks available on NaCo, the "Broad Band (BB) 9 holes" and the "7 holes" masks. Observational details such as mask used, integration time (DIT), size of datacube, and number of exposures for each science target are summarized in Table 1. The operational m ...
Diapositiva 1 - INAF-Osservatorio Astronomico di Bologna
... Constraints on the mechanism(s) acting at z>2 less stringent: They can increase their mass and enlarge their size by subsequent mergers (major and minor/satellite) and through starburts till z~2.5 (contrary to oETGs). Different progenitors oETGs: we should see them as they are (younger) till z~3-3.5 ...
... Constraints on the mechanism(s) acting at z>2 less stringent: They can increase their mass and enlarge their size by subsequent mergers (major and minor/satellite) and through starburts till z~2.5 (contrary to oETGs). Different progenitors oETGs: we should see them as they are (younger) till z~3-3.5 ...
Evolution of the Highest Redshift Quasars
... – How closely tied are the earliest SBHs and galaxies? Or are we just picking up early starters in term of BH accretion in the most luminous quasars? ...
... – How closely tied are the earliest SBHs and galaxies? Or are we just picking up early starters in term of BH accretion in the most luminous quasars? ...
Elemental ratios in stars vs planets
... further than 0.3 AU, the ratios attain solar values. 4.2. C/O ratio in solids Figures 4 shows the mode value of C/O in solids (refractory species and ices) for the three populations versus the stellar ratio. The C/O ratio in icy and giant planets appears to be very weakly dependent on the C/O ratio ...
... further than 0.3 AU, the ratios attain solar values. 4.2. C/O ratio in solids Figures 4 shows the mode value of C/O in solids (refractory species and ices) for the three populations versus the stellar ratio. The C/O ratio in icy and giant planets appears to be very weakly dependent on the C/O ratio ...
Energetic neutral atoms around HD 209458b
... The stellar wind density and temperature have also been scaled from average solar conditions for our Sun using relations given by Russell et al. (1988). Given the close proximity of HD 209458b to its host star the choice of stellar wind parameters has to be looked at in some detail. At the Sun we di ...
... The stellar wind density and temperature have also been scaled from average solar conditions for our Sun using relations given by Russell et al. (1988). Given the close proximity of HD 209458b to its host star the choice of stellar wind parameters has to be looked at in some detail. At the Sun we di ...
Radiation pressure from massive star clusters as a launching
... For our purpose, we can ignore the fact that the shells are clumpy. Since radiation pressure supplies the bulk of the momentum absorbed by the gas, the clumpy nature of the ISM will not prevent the formation of a bubble: any gas in the vicinity will absorb momentum from the radiation field. Some ver ...
... For our purpose, we can ignore the fact that the shells are clumpy. Since radiation pressure supplies the bulk of the momentum absorbed by the gas, the clumpy nature of the ISM will not prevent the formation of a bubble: any gas in the vicinity will absorb momentum from the radiation field. Some ver ...
![arXiv:1210.2471v1 [astro-ph.EP] 9 Oct 2012 Exoplanet Detection](http://s1.studyres.com/store/data/015975823_1-e4b4b3613f38bbff39746aa9bc12073b-300x300.png)
arXiv:1210.2471v1 [astro-ph.EP] 9 Oct 2012 Exoplanet Detection
... of the parent star. Although the emission of exoplanets is indeed quite faint, it is generally the problem of detecting this emission in the proximity of the much brighter stellar source that presents the most severe practical obstacle to direct detection. The disentangling of stellar and planetary ...
... of the parent star. Although the emission of exoplanets is indeed quite faint, it is generally the problem of detecting this emission in the proximity of the much brighter stellar source that presents the most severe practical obstacle to direct detection. The disentangling of stellar and planetary ...
Giant star seismology
... Asteroseismology – the study of global properties of stars and their internal structure through their global intrinsic oscillations – is already more than a century old. An early remarkable result was obtained for Cepheids revealing the period-luminosity relation (Leavitt and Pickering, 1912), which ...
... Asteroseismology – the study of global properties of stars and their internal structure through their global intrinsic oscillations – is already more than a century old. An early remarkable result was obtained for Cepheids revealing the period-luminosity relation (Leavitt and Pickering, 1912), which ...
Beasts of the Southern Wild: Discovery of nine Ultra Faint satellites
... assumption of the shape of their galactocentric radial distribution. Given that only a handful of such objects are known today, their radial profile is not observationally constrained. However, if it is assumed that the faintest of the UFDs are linked to the small-mass field dark matter (DM) sub-hal ...
... assumption of the shape of their galactocentric radial distribution. Given that only a handful of such objects are known today, their radial profile is not observationally constrained. However, if it is assumed that the faintest of the UFDs are linked to the small-mass field dark matter (DM) sub-hal ...
f) Organizing the Elements Metals Nonmetals and
... Structure of an Atom If you could look into a single atom, what might you see? Figuring out what atoms are made of hasn't been easy. Theories about their shape and structure have changed many times and continue to be improved even now. Until about 100 years ago, scientists thought atoms were the sma ...
... Structure of an Atom If you could look into a single atom, what might you see? Figuring out what atoms are made of hasn't been easy. Theories about their shape and structure have changed many times and continue to be improved even now. Until about 100 years ago, scientists thought atoms were the sma ...
Galactic Molecular Clouds and Their Place in the
... MCs are the sites where all known star formation is thought to occur, hence whenever an area containing young stars reside, it is assumed that one will also find a MC, Blitz & Williams (1999). Knowledge of these stellar birthplaces assist in not only in models of stellar but also Galactic evolution, ...
... MCs are the sites where all known star formation is thought to occur, hence whenever an area containing young stars reside, it is assumed that one will also find a MC, Blitz & Williams (1999). Knowledge of these stellar birthplaces assist in not only in models of stellar but also Galactic evolution, ...
Protoplanetary disks, jets, and the birth of the stars
... Stars form as a result of the collapse of dense cores of molecular gas and dust, which arise from the fragmentation of interstellar (parsec-scale) molecular clouds. Because of the initial rotation of the core, matter does not fall directly onto the central (proto)star but through a circumstellar acc ...
... Stars form as a result of the collapse of dense cores of molecular gas and dust, which arise from the fragmentation of interstellar (parsec-scale) molecular clouds. Because of the initial rotation of the core, matter does not fall directly onto the central (proto)star but through a circumstellar acc ...
EXCITATION OF RADIAL P-MODES IN THE SUN AND STARS ROBERT STEIN
... compressibility. Excitation decreases at high frequencies because convection lacks high frequency motions. Finally, we apply our formula to the excitation of stellar p-mode oscillations using simulations of nine stars near the main sequence and a cool sub-giant (Section 6). We find that the total ex ...
... compressibility. Excitation decreases at high frequencies because convection lacks high frequency motions. Finally, we apply our formula to the excitation of stellar p-mode oscillations using simulations of nine stars near the main sequence and a cool sub-giant (Section 6). We find that the total ex ...
AN INITIAL MASS FUNCTION STUDY OF THE DWARF Please share
... Traditional methods for IMF measurements in the Milky Way, Large Magellanic Cloud (LMC), and Small Magellanic Cloud (SMC) are to count individual stars in clusters 3–5 Myr old that still retain their most massive stars (Anderson et al. 2009; Sabbi et al. 2008; Sirianni et al. 2000, for example). Ge ...
... Traditional methods for IMF measurements in the Milky Way, Large Magellanic Cloud (LMC), and Small Magellanic Cloud (SMC) are to count individual stars in clusters 3–5 Myr old that still retain their most massive stars (Anderson et al. 2009; Sabbi et al. 2008; Sirianni et al. 2000, for example). Ge ...
Stellar evolution
Stellar evolution is the process by which a star changes during its lifetime. Depending on the mass of the star, this lifetime ranges from a few million years for the most massive to trillions of years for the least massive, which is considerably longer than the age of the universe. The table shows the lifetimes of stars as a function of their masses. All stars are born from collapsing clouds of gas and dust, often called nebulae or molecular clouds. Over the course of millions of years, these protostars settle down into a state of equilibrium, becoming what is known as a main-sequence star.Nuclear fusion powers a star for most of its life. Initially the energy is generated by the fusion of hydrogen atoms at the core of the main-sequence star. Later, as the preponderance of atoms at the core becomes helium, stars like the Sun begin to fuse hydrogen along a spherical shell surrounding the core. This process causes the star to gradually grow in size, passing through the subgiant stage until it reaches the red giant phase. Stars with at least half the mass of the Sun can also begin to generate energy through the fusion of helium at their core, whereas more-massive stars can fuse heavier elements along a series of concentric shells. Once a star like the Sun has exhausted its nuclear fuel, its core collapses into a dense white dwarf and the outer layers are expelled as a planetary nebula. Stars with around ten or more times the mass of the Sun can explode in a supernova as their inert iron cores collapse into an extremely dense neutron star or black hole. Although the universe is not old enough for any of the smallest red dwarfs to have reached the end of their lives, stellar models suggest they will slowly become brighter and hotter before running out of hydrogen fuel and becoming low-mass white dwarfs.Stellar evolution is not studied by observing the life of a single star, as most stellar changes occur too slowly to be detected, even over many centuries. Instead, astrophysicists come to understand how stars evolve by observing numerous stars at various points in their lifetime, and by simulating stellar structure using computer models.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.