ch 15 notes
... Measuring Distances to Stars Astronomers often use parallax to measure distances to nearby stars (within a few hundred light years, that is). ...
... Measuring Distances to Stars Astronomers often use parallax to measure distances to nearby stars (within a few hundred light years, that is). ...
stars - KIAS
... • The seismic estimations of rotation periods and asynchronism of primary oEA star are as accurate as the measured pulsation periods. For a several month long duration observations the accuracy is of order values of 10 –5 . • This means that we have a very precise tool for the study of of rotation p ...
... • The seismic estimations of rotation periods and asynchronism of primary oEA star are as accurate as the measured pulsation periods. For a several month long duration observations the accuracy is of order values of 10 –5 . • This means that we have a very precise tool for the study of of rotation p ...
Chapter 15 Stars, Galaxies, and Universe Galaxies
... Measuring Distances to Stars Astronomers often use parallax to measure distances to nearby stars (within a few hundred light years, that is). ...
... Measuring Distances to Stars Astronomers often use parallax to measure distances to nearby stars (within a few hundred light years, that is). ...
SMA Observations of AB Aur
... The ring-like structure is most likely due to enhancement of the disk surface density. The NE part of the dust disk might have a larger dust spectral index than the SW part. ...
... The ring-like structure is most likely due to enhancement of the disk surface density. The NE part of the dust disk might have a larger dust spectral index than the SW part. ...
Observational Astronomy - Lecture 10 Galaxies
... mass of galaxies is in the form of “Dark Matter”. This matter is not made up of ordinary matter (i.e. it is not made up of atoms). The ordinary matter (which astronomers typically call “baryonic” matter), has the following components: Stars and planets - these account for perhaps 10-50% of the ordin ...
... mass of galaxies is in the form of “Dark Matter”. This matter is not made up of ordinary matter (i.e. it is not made up of atoms). The ordinary matter (which astronomers typically call “baryonic” matter), has the following components: Stars and planets - these account for perhaps 10-50% of the ordin ...
The HARPS-N Rocky Planet Search I. HD219134b: A transiting
... The GTO (Guaranteed Time Observation) granted to the HARPS-N consortium is dedicated to two programs: i) the confirmation of the planetary nature and the characterization of Kepler candidates and ii) a Rocky Planet Search (RPS). The aim of the RPS program is to perform a systematic search for low-ma ...
... The GTO (Guaranteed Time Observation) granted to the HARPS-N consortium is dedicated to two programs: i) the confirmation of the planetary nature and the characterization of Kepler candidates and ii) a Rocky Planet Search (RPS). The aim of the RPS program is to perform a systematic search for low-ma ...
Coming Home - Marcia Bartusiak
... he enigmatic infrared objects do not resemble individual stars; one looks like it might be a particularly dense and energetic cluster of stars. Whatever they are, their combined power could account for much of the hubbub in the galactic cen ter. If so, then there is no need for a supermassive black ...
... he enigmatic infrared objects do not resemble individual stars; one looks like it might be a particularly dense and energetic cluster of stars. Whatever they are, their combined power could account for much of the hubbub in the galactic cen ter. If so, then there is no need for a supermassive black ...
3D Reconstruction and Visualization of Spiral Galaxies
... light show emissions from wavelengths of 3.6 microns (blue), 8 microns (green), and 24.0 microns (red). Images in near-infrared collected at 3.6 micron trace the distribution of older and redder stars and are virtually unaffected by obscuring dust. As one moves to longer wavelengths, the spiral arms ...
... light show emissions from wavelengths of 3.6 microns (blue), 8 microns (green), and 24.0 microns (red). Images in near-infrared collected at 3.6 micron trace the distribution of older and redder stars and are virtually unaffected by obscuring dust. As one moves to longer wavelengths, the spiral arms ...
Globular cluster absolute ages from cooling brown dwarfs
... the different correlations. It is also worth mentioning that what we observe from Earth is not the stellar luminosity and temperature, but their magnitudes in different filters. In order to convert these observations into parameters that we can compare with our stellar evolution models, we have to e ...
... the different correlations. It is also worth mentioning that what we observe from Earth is not the stellar luminosity and temperature, but their magnitudes in different filters. In order to convert these observations into parameters that we can compare with our stellar evolution models, we have to e ...
The role of the initial surface density profiles of the disc on giant
... Hartmann et al. (1998). This simple formula, which is characterized by a power law in the inner part of the disc and an exponential decay in the outer part, is a reasonable alternative for use in protoplanetary discs because it is simple, it matches the protoplanetary discs observations (Andrews et ...
... Hartmann et al. (1998). This simple formula, which is characterized by a power law in the inner part of the disc and an exponential decay in the outer part, is a reasonable alternative for use in protoplanetary discs because it is simple, it matches the protoplanetary discs observations (Andrews et ...
LesHouches_VanGrootel
... Conclusion: Thanks to g-mode seismology, we have access to • Global parameters of the star (mass, radius, luminosity, etc.) • Structural and core parameters (Menv, Mcore, core composition, etc) ...
... Conclusion: Thanks to g-mode seismology, we have access to • Global parameters of the star (mass, radius, luminosity, etc.) • Structural and core parameters (Menv, Mcore, core composition, etc) ...
Spectral Fingerprints of Earth-like Planets Around FGK Stars
... the planet (see also Schindler and Kasting, 2000). The temperature in each layer is calculated from the difference between the incoming and outgoing flux and the heat capacity of the atmosphere in each layer. If the lapse rate of a given layer is larger than the adiabatic lapse rate, it is adjusted ...
... the planet (see also Schindler and Kasting, 2000). The temperature in each layer is calculated from the difference between the incoming and outgoing flux and the heat capacity of the atmosphere in each layer. If the lapse rate of a given layer is larger than the adiabatic lapse rate, it is adjusted ...
The slow-neutron capture process at low metallicity
... Using the data and classification of Masseron et al. (2010) ...
... Using the data and classification of Masseron et al. (2010) ...
Are Planetary Systems Filled to Capacity
... profoundly change its large-scale configuration at a later time. A pool table provides a familiar example: Microscopic variations in the trajectory of a billiard ball, especially one involved in multiple collisions, can completely alter the outcome of the game. Chaotic systems are deterministic, in ...
... profoundly change its large-scale configuration at a later time. A pool table provides a familiar example: Microscopic variations in the trajectory of a billiard ball, especially one involved in multiple collisions, can completely alter the outcome of the game. Chaotic systems are deterministic, in ...
Pre-supernova evolution of massive stars
... temperature reached is smaller than required for carbon fusion. During the latest stages of evolution on the AGB these stars undergo strong mass loss which removes the remaining envelope, so that their final remnants are C-O white dwarfs. The evolution of massive stars is different in two important ...
... temperature reached is smaller than required for carbon fusion. During the latest stages of evolution on the AGB these stars undergo strong mass loss which removes the remaining envelope, so that their final remnants are C-O white dwarfs. The evolution of massive stars is different in two important ...
2. The Universe Is Expanding and Evolving
... We now know that the entire universe is both expanding and evolving. These two remarkable facts have been established beyond doubt over the past century. The simple observation that the sky is dark at night indicates that the universe cannot be infinite and unchanging, comprised of an infinite numbe ...
... We now know that the entire universe is both expanding and evolving. These two remarkable facts have been established beyond doubt over the past century. The simple observation that the sky is dark at night indicates that the universe cannot be infinite and unchanging, comprised of an infinite numbe ...
Herschel Space Observatory - Science and Technology Facilities
... in our Galaxy, shown in red, as well as the material thrown out by the supernova itself. The ring of gas and dust contains enough material to form 25,000 Earths, but this is still only a fraction of the mass of the Sun. Supernovae are one possible source of all the dust we see. The star “CW Leonis” ...
... in our Galaxy, shown in red, as well as the material thrown out by the supernova itself. The ring of gas and dust contains enough material to form 25,000 Earths, but this is still only a fraction of the mass of the Sun. Supernovae are one possible source of all the dust we see. The star “CW Leonis” ...
LIAC_VanGrootel - ORBi
... • Assuming orbits aligned with equatorial plane • Most relevant parameter range: low values for the albedo and β ...
... • Assuming orbits aligned with equatorial plane • Most relevant parameter range: low values for the albedo and β ...
Slide 1
... • Compare to the actual period pulse of the Crab Nebula: which is 0.033 seconds or about 29 times per second. ...
... • Compare to the actual period pulse of the Crab Nebula: which is 0.033 seconds or about 29 times per second. ...
Abundance Anomalies In Tidal Disruption Events
... isotope ratios, but these will not be observable in TDEs because of Doppler line broadening. For a normal star, these internal changes have no external consequences until close to death, when convection on the giant branch can mix material from the hydrogen burning zone to the surface (“dredge up”). ...
... isotope ratios, but these will not be observable in TDEs because of Doppler line broadening. For a normal star, these internal changes have no external consequences until close to death, when convection on the giant branch can mix material from the hydrogen burning zone to the surface (“dredge up”). ...
this article
... rapid depletion of material from the outer envelope of the star means that while AGB mass loss may last for > 105 yrs, this extremely high mass-loss SW phase must have a relatively short duration (a few × 104 years; Volk et al. 2000). During their ascent of the AGB, these stars also evolve chemica ...
... rapid depletion of material from the outer envelope of the star means that while AGB mass loss may last for > 105 yrs, this extremely high mass-loss SW phase must have a relatively short duration (a few × 104 years; Volk et al. 2000). During their ascent of the AGB, these stars also evolve chemica ...
Nucleosynthesis, the r-Process, Abundances and Jim Truran
... Element Abundances in Metal-deficient Stars Cowan, Thielemann & Truran (1991) The r-Process and Nucleochronology Fields, Truran & Cowan (2002) A Simple Model for rProcess Scatter and Halo Evolution Truran et al. (2002) Probing the Neutron Capture Nucleosynthesis History of Galactic Matter ...
... Element Abundances in Metal-deficient Stars Cowan, Thielemann & Truran (1991) The r-Process and Nucleochronology Fields, Truran & Cowan (2002) A Simple Model for rProcess Scatter and Halo Evolution Truran et al. (2002) Probing the Neutron Capture Nucleosynthesis History of Galactic Matter ...
Stellar death - Department of Astronomy
... Maximum mass of a white dwarf White dwarfs with larger masses have smaller radii The pressure within a white dwarf depends only on density, not on temperature, so larger density is needed to balance gravity At M = 1.4M⊙ , degeneracy pressure can no longer provide enough pressure Radius of white dwa ...
... Maximum mass of a white dwarf White dwarfs with larger masses have smaller radii The pressure within a white dwarf depends only on density, not on temperature, so larger density is needed to balance gravity At M = 1.4M⊙ , degeneracy pressure can no longer provide enough pressure Radius of white dwa ...
Presentation (PowerPoint File)
... Simulations of star formation in cores with r r-1.5 Equation of state: isothermal or barotropic above 10^-14 g cm-3 Isothermal collapse results in many small fragments; barotropic collapse in a few. In no case did a massive star form (although simulation ran only until ~ 10% of mass had gone into ...
... Simulations of star formation in cores with r r-1.5 Equation of state: isothermal or barotropic above 10^-14 g cm-3 Isothermal collapse results in many small fragments; barotropic collapse in a few. In no case did a massive star form (although simulation ran only until ~ 10% of mass had gone into ...
Planetary nebula
A planetary nebula, often abbreviated as PN or plural PNe, is a kind of emission nebula consisting of an expanding glowing shell of ionized gas ejected from old red giant stars late in their lives. The word ""nebula"" is Latin for mist or cloud and the term ""planetary nebula"" is a misnomer that originated in the 1780s with astronomer William Herschel because when viewed through his telescope, these objects appeared to him to resemble the rounded shapes of planets. Herschel's name for these objects was popularly adopted and has not been changed. They are a relatively short-lived phenomenon, lasting a few tens of thousands of years, compared to a typical stellar lifetime of several billion years.A mechanism for formation of most planetary nebulae is thought to be the following: at the end of the star's life, during the red giant phase, the outer layers of the star are expelled by strong stellar winds. Eventually, after most of the red giant's atmosphere is dissipated, the exposed hot, luminous core emits ultraviolet radiation to ionize the ejected outer layers of the star. Absorbed ultraviolet light energises the shell of nebulous gas around the central star, appearing as a bright coloured planetary nebula at several discrete visible wavelengths.Planetary nebulae may play a crucial role in the chemical evolution of the Milky Way, returning material to the interstellar medium from stars where elements, the products of nucleosynthesis (such as carbon, nitrogen, oxygen and neon), have been created. Planetary nebulae are also observed in more distant galaxies, yielding useful information about their chemical abundances.In recent years, Hubble Space Telescope images have revealed many planetary nebulae to have extremely complex and varied morphologies. About one-fifth are roughly spherical, but the majority are not spherically symmetric. The mechanisms which produce such a wide variety of shapes and features are not yet well understood, but binary central stars, stellar winds and magnetic fields may play a role.