Core Formation in Giant Gaseous Protoplanets
... enough to let the grains survive. We follow the silicate grains as they grow and sediment towards the center of the protoplanet. In convective regions, the grains are carried by the convective eddies until they grow large enough to decouple from the gas and settle to the center. We find that once gr ...
... enough to let the grains survive. We follow the silicate grains as they grow and sediment towards the center of the protoplanet. In convective regions, the grains are carried by the convective eddies until they grow large enough to decouple from the gas and settle to the center. We find that once gr ...
Dyson Spheres around White Dwarfs arXiv:1503.04376
... it would stand out in astronomical IR images. The simplest form of the Dyson Sphere, a solid spherical shell, is problematic: It would be subject to unaccetably large stresses and its equilibrium around the star is neutral at best (as opposed to stable, see Appendix). Therefore, variants were sugges ...
... it would stand out in astronomical IR images. The simplest form of the Dyson Sphere, a solid spherical shell, is problematic: It would be subject to unaccetably large stresses and its equilibrium around the star is neutral at best (as opposed to stable, see Appendix). Therefore, variants were sugges ...
Antlia, the Machine Pneumatique
... east of S Antliae and is certainly outstanding in appearances. Although not that bright, this galaxy is easily seen as a north-west to south-east oval. Higher power reveals that it gradually brightens towards a well-defined, but small nucleus. The north-eastern and south-western outer edges appear g ...
... east of S Antliae and is certainly outstanding in appearances. Although not that bright, this galaxy is easily seen as a north-west to south-east oval. Higher power reveals that it gradually brightens towards a well-defined, but small nucleus. The north-eastern and south-western outer edges appear g ...
Manuscript - Kapteyn Astronomical Institute
... In the case of gas-rich systems –which are a majority at the low mass end, encounters with dark satellites will be less efficient at changing the structure of the host dwarf galaxy, because much of the orbital energy will be absorbed by the gas, leading to less vertical heating. However, we may expe ...
... In the case of gas-rich systems –which are a majority at the low mass end, encounters with dark satellites will be less efficient at changing the structure of the host dwarf galaxy, because much of the orbital energy will be absorbed by the gas, leading to less vertical heating. However, we may expe ...
Misalignment & Nucleosynthesis in Microquasars Yousaf M. Butt , Thomas J. Maccarone
... Since the position angles of BHXB orbital planes remain unmeasured, we argue that a significant fraction of microquasar jets could lie close enough to their orbital planes so as to periodically impact the companion stars, and initiate spallative and fusion nuclear reactions thereon. In this way the ...
... Since the position angles of BHXB orbital planes remain unmeasured, we argue that a significant fraction of microquasar jets could lie close enough to their orbital planes so as to periodically impact the companion stars, and initiate spallative and fusion nuclear reactions thereon. In this way the ...
PDF
... 30] and non-‐linear metric perturbations [31, 32, 33], blue spectra of density fluctuations [34, 35, 36, 37, 38, 39], a softening of the equation of state [40, 34, 35], development of gravitational ins ...
... 30] and non-‐linear metric perturbations [31, 32, 33], blue spectra of density fluctuations [34, 35, 36, 37, 38, 39], a softening of the equation of state [40, 34, 35], development of gravitational ins ...
Astronomy Essay Questions
... Describe and discuss neutron stars and pulsars. What are they and how are the related to each other? Describe their physical characteristics. How are they observed? Where do they fit into the process of stellar evolution? Describe and discuss neutron stars. What are they? Describe their physical ch ...
... Describe and discuss neutron stars and pulsars. What are they and how are the related to each other? Describe their physical characteristics. How are they observed? Where do they fit into the process of stellar evolution? Describe and discuss neutron stars. What are they? Describe their physical ch ...
Slide 1
... a large fraction of gas & stars tidally stripped from the dwarf galaxy during interaction leaving only stars most closely bound to the BH (GC-like) star formation triggered by tidal interactions compatible with eccentric binary scenario presence of dust lanes in ESO243-49 could provide evide ...
... a large fraction of gas & stars tidally stripped from the dwarf galaxy during interaction leaving only stars most closely bound to the BH (GC-like) star formation triggered by tidal interactions compatible with eccentric binary scenario presence of dust lanes in ESO243-49 could provide evide ...
A method for determining the V magnitude of asteroids from CCD
... of comparison star data. The All-Sky Survey (TASS), for example, is calibrated against Tycho-2 stars.19 GUIDE states that ‘In most cases the precision provided by Tycho is much greater than all earlier catalogues. About the only case in which Tycho data would be ignored is if Hipparcos data is avail ...
... of comparison star data. The All-Sky Survey (TASS), for example, is calibrated against Tycho-2 stars.19 GUIDE states that ‘In most cases the precision provided by Tycho is much greater than all earlier catalogues. About the only case in which Tycho data would be ignored is if Hipparcos data is avail ...
Chapter 27 Quasars, Active Galaxies, and Gamma
... • Early radio telescopes found radio emission from stars, nebulae, and some galaxies. • There were also point-like, or star-like, radio sources which varied rapidly these are the `quasi-stellar’ radio sources or quasars. • In visible light quasars appear as points, like stars. ...
... • Early radio telescopes found radio emission from stars, nebulae, and some galaxies. • There were also point-like, or star-like, radio sources which varied rapidly these are the `quasi-stellar’ radio sources or quasars. • In visible light quasars appear as points, like stars. ...
Pre-main sequence stars, emission stars and recent star formation in
... studied here are Berkeley 86, NGC 6910, IC 4996, Berkeley 87 and Biurakan 2. We aim to combine the ages and the star formation duration in these clusters to understand how the star formation proceeded in the Cygnus region. A number of stars are known to show Hα emission in this region. The photometr ...
... studied here are Berkeley 86, NGC 6910, IC 4996, Berkeley 87 and Biurakan 2. We aim to combine the ages and the star formation duration in these clusters to understand how the star formation proceeded in the Cygnus region. A number of stars are known to show Hα emission in this region. The photometr ...
Stars
... Life Track After Main Sequence • Observations of star clusters show that a star becomes larger, redder, and more luminous after its time on the main sequence is over. • At the end of their main sequence life time - when hydrogen in the core is exhausted - stars ascend the red giant branch. © 2007 P ...
... Life Track After Main Sequence • Observations of star clusters show that a star becomes larger, redder, and more luminous after its time on the main sequence is over. • At the end of their main sequence life time - when hydrogen in the core is exhausted - stars ascend the red giant branch. © 2007 P ...
Circumstellar grains: radiation pressure and
... Qabs is the efficiency factor for absorption and B(λ, Tg ) is Planck’s function. This equation is solved for R, for given values of Tg . For the present study, we have considered eleven stars of various spectral types in an attempt to span a wide range of situations (Table 1). Ten of them are real o ...
... Qabs is the efficiency factor for absorption and B(λ, Tg ) is Planck’s function. This equation is solved for R, for given values of Tg . For the present study, we have considered eleven stars of various spectral types in an attempt to span a wide range of situations (Table 1). Ten of them are real o ...
THE PRIMORDIAL HELIUM ABUNDANCE Manuel Peimbert
... the study of cosmology and the chemical evolution of galaxies. Over the years the increase in the accuracy of the helium abundance by mass, Y, of different objects and in the accuracy of the predictions of the primordial helium abundance by unit mass, YP (also known as the primordial helium mass fra ...
... the study of cosmology and the chemical evolution of galaxies. Over the years the increase in the accuracy of the helium abundance by mass, Y, of different objects and in the accuracy of the predictions of the primordial helium abundance by unit mass, YP (also known as the primordial helium mass fra ...
Universe, Dark Energy and Dark Matter
... around as and this uniformity applies not only to their distribution but also to the law of increase of their velocities as they move away from us. How can it be explained? It may be suggested that man takes the central position in the Universe and all the galaxies are running away from us. Other sc ...
... around as and this uniformity applies not only to their distribution but also to the law of increase of their velocities as they move away from us. How can it be explained? It may be suggested that man takes the central position in the Universe and all the galaxies are running away from us. Other sc ...
Using Atmospheric Cherenkov Telescope arrays as Intensity Interferometers S. LeBohec and J. Holder
... The Narrabri interferometer consisted of two telescopes 6.5m in diameter with an 11m focal length. The telescopes were carried on trucks running on a circular railway track 188m in diameter. This allowed for a baseline from 10m to 188m to track any star while keeping the line joining the two telesco ...
... The Narrabri interferometer consisted of two telescopes 6.5m in diameter with an 11m focal length. The telescopes were carried on trucks running on a circular railway track 188m in diameter. This allowed for a baseline from 10m to 188m to track any star while keeping the line joining the two telesco ...
Infrared spectroscopy of exoplanets: observational constraints
... and resolving power The infrared spectrum of an exoplanet is composed of two main components: the reflected/scattered stellar flux, which peaks in the UV, visible or near-infrared range (depending on the spectral type of the host star), and the thermal emission which dominates at longer wavelengths. I ...
... and resolving power The infrared spectrum of an exoplanet is composed of two main components: the reflected/scattered stellar flux, which peaks in the UV, visible or near-infrared range (depending on the spectral type of the host star), and the thermal emission which dominates at longer wavelengths. I ...
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.