Ages of young stars
... individual objects. A reliable age scale is established above 20 Myr from measurement of the Lithium Depletion Boundary (LDB) in young clusters, and consistency is shown between these ages and those from the upper main sequence and the main sequence turn-off – if modest core convection and rotation ...
... individual objects. A reliable age scale is established above 20 Myr from measurement of the Lithium Depletion Boundary (LDB) in young clusters, and consistency is shown between these ages and those from the upper main sequence and the main sequence turn-off – if modest core convection and rotation ...
Ages of Young Stars
... of our Solar System from meteorites because we can apply radiometric dating techniques to samples in a laboratory. From this we infer the Sun’s age, a very precise one, but even the Sun itself does not directly reveal its age in its visible properties. The techniques for age-dating stars, and thereb ...
... of our Solar System from meteorites because we can apply radiometric dating techniques to samples in a laboratory. From this we infer the Sun’s age, a very precise one, but even the Sun itself does not directly reveal its age in its visible properties. The techniques for age-dating stars, and thereb ...
NSDL/NSTA Web Seminar: Celebrating Astronomy: A Star`s Story
... http://www.compadre.org/Astronomy Hubble Space Telescope http://hubblesite.org International Year of Astronomy 2009 http://astronomy2009.us http://astronomy2009.org ...
... http://www.compadre.org/Astronomy Hubble Space Telescope http://hubblesite.org International Year of Astronomy 2009 http://astronomy2009.us http://astronomy2009.org ...
Starburst Galaxies Under the Microscope: High
... Starburst galaxies are unique laboratories. Starburst episodes are phases in the evolution of galaxies that are by definition transient, and during which they convert a significant fraction of their gas reservoirs into stars. During a starburst phase a galaxy thus evolves rapidly in stellar, gas, du ...
... Starburst galaxies are unique laboratories. Starburst episodes are phases in the evolution of galaxies that are by definition transient, and during which they convert a significant fraction of their gas reservoirs into stars. During a starburst phase a galaxy thus evolves rapidly in stellar, gas, du ...
The Ages of Stars
... Yet age lies at the heart of stellar evolution, for how can there be evolution About Stellar Ages? without the passage of time? Sometimes our desire to know ages is satisfied if we (see p. 46) can place events in the correct sequence and understand the relative duration of phases. But often we need ...
... Yet age lies at the heart of stellar evolution, for how can there be evolution About Stellar Ages? without the passage of time? Sometimes our desire to know ages is satisfied if we (see p. 46) can place events in the correct sequence and understand the relative duration of phases. But often we need ...
Chapter 17--Star Stuff
... atoms to pair up to form hydrogen molecules (H2). The relatively rare atoms of elements heavier than helium can also form molecules, such as carbon monoxide or water, or tiny, solid grains of dust. More important, the cold temperatures and high densities allow gravity to overcome thermal pressure mo ...
... atoms to pair up to form hydrogen molecules (H2). The relatively rare atoms of elements heavier than helium can also form molecules, such as carbon monoxide or water, or tiny, solid grains of dust. More important, the cold temperatures and high densities allow gravity to overcome thermal pressure mo ...
The ages of pre-main-sequence stars
... tracks. On the assumption that the stellar models are accurate, we demonstrate that, if the metallicity is known, the mass obtained is a good estimate. However, the age determination can be very misleading, because it is significantly (generally different by a factor of 2 to 5) dependent on the accr ...
... tracks. On the assumption that the stellar models are accurate, we demonstrate that, if the metallicity is known, the mass obtained is a good estimate. However, the age determination can be very misleading, because it is significantly (generally different by a factor of 2 to 5) dependent on the accr ...
Astronomy Astrophysics - Niels Bohr Institutet
... effort has been devoted to the fundamental issue of determining reliable isochrone ages for as many stars as possible, and we believe that a rather more realistic assessment of the errors of such ages has been obtained. Finally, we have computed individual Galactic orbits for all stars with adequate ...
... effort has been devoted to the fundamental issue of determining reliable isochrone ages for as many stars as possible, and we believe that a rather more realistic assessment of the errors of such ages has been obtained. Finally, we have computed individual Galactic orbits for all stars with adequate ...
ASTRO-114--Lecture 47-
... sound like? It’s static. It’s radio static. And so you point your radio telescope over here and you don’t hear any radio static, you know there’s no hydrogen over there. You point it somewhere else, you pick up a lot of radio static at that particular wavelength, and you say, “Aha. There’s a big clo ...
... sound like? It’s static. It’s radio static. And so you point your radio telescope over here and you don’t hear any radio static, you know there’s no hydrogen over there. You point it somewhere else, you pick up a lot of radio static at that particular wavelength, and you say, “Aha. There’s a big clo ...
SPACETIME SINGULARITIES: The STORY of BLACK HOLES
... before an explosive rebound takes place, and the explosion is not all that symmetric. In section C.2(a) below we will take a more extended look at what supernovae and their remnants look like, to see this. However, it can be shown that if the initial collapsing material does not have a net angular m ...
... before an explosive rebound takes place, and the explosion is not all that symmetric. In section C.2(a) below we will take a more extended look at what supernovae and their remnants look like, to see this. However, it can be shown that if the initial collapsing material does not have a net angular m ...
Here
... Effect of Seeing One important aspect in the study of the surface brightness of galaxies is the characterization of their surface brightness profiles, that is the dependence of the surface brightness upon the projected distance to the center of the galaxy. However, turbulence in the upper atmospher ...
... Effect of Seeing One important aspect in the study of the surface brightness of galaxies is the characterization of their surface brightness profiles, that is the dependence of the surface brightness upon the projected distance to the center of the galaxy. However, turbulence in the upper atmospher ...
Luminosity of sun
... Remember, lifespan shorter for hot, massive, blue stars Stars in a cluster form all at the same time. ...
... Remember, lifespan shorter for hot, massive, blue stars Stars in a cluster form all at the same time. ...
A Reappraisal of The Habitability of Planets around M Dwarf Stars
... magnitude measurements, where the letter indicates the spectral band and response of the receiver, e.g., MV denotes absolute magnitude as measured in the visual or V band. The difficulty comes in practice when not all “V” bands are the same, but that level of detail is beyond the scope of this paper ...
... magnitude measurements, where the letter indicates the spectral band and response of the receiver, e.g., MV denotes absolute magnitude as measured in the visual or V band. The difficulty comes in practice when not all “V” bands are the same, but that level of detail is beyond the scope of this paper ...
A re-appraisal of the habitability of planets around M dwarf
... magnitude measurements, where the letter indicates the spectral band and response of the receiver, e.g., MV denotes absolute magnitude as measured in the visual or V band. The difficulty comes in practice when not all “V” bands are the same, but that level of detail is beyond the scope of this paper ...
... magnitude measurements, where the letter indicates the spectral band and response of the receiver, e.g., MV denotes absolute magnitude as measured in the visual or V band. The difficulty comes in practice when not all “V” bands are the same, but that level of detail is beyond the scope of this paper ...
Origin and evolution of magnetars
... We have also constructed a P − Ṗ diagram which is shown in Fig. 2, where our ROSAT-selected objects are compared with the observations of all magnetars with known Ṗ . Thus, among the observed objects we have also included SGR 0526−66, which is located in the LMC, and CXOU J010043−721134, which is ...
... We have also constructed a P − Ṗ diagram which is shown in Fig. 2, where our ROSAT-selected objects are compared with the observations of all magnetars with known Ṗ . Thus, among the observed objects we have also included SGR 0526−66, which is located in the LMC, and CXOU J010043−721134, which is ...
Calculate the Mass of the Milky Way Galaxy
... Few of the points fall exactly on the line. This is because all galaxies have some additional residual motion in addition to the pure expansion. This is referred to as the "cosmic velocity dispersion" or "cosmic scatter" and is probably due to the fact that the gas clouds that formed the galaxies al ...
... Few of the points fall exactly on the line. This is because all galaxies have some additional residual motion in addition to the pure expansion. This is referred to as the "cosmic velocity dispersion" or "cosmic scatter" and is probably due to the fact that the gas clouds that formed the galaxies al ...
EXPLORING FUNDAMENTAL PHYSICS WITH NEUTRON STARS
... constitute to date the majority of the population, this could be an observational bias; indeed, in the last two decades new satellites have been changing our view about neutron stars: for example, the Fermi satellite has discovered a large new population of g-ray pulsars, while only Geminga was know ...
... constitute to date the majority of the population, this could be an observational bias; indeed, in the last two decades new satellites have been changing our view about neutron stars: for example, the Fermi satellite has discovered a large new population of g-ray pulsars, while only Geminga was know ...
Stellar kinematics
Stellar kinematics is the study of the movement of stars without needing to understand how they acquired their motion. This differs from stellar dynamics, which takes into account gravitational effects. The motion of a star relative to the Sun can provide useful information about the origin and age of a star, as well as the structure and evolution of the surrounding part of the Milky Way.In astronomy, it is widely accepted that most stars are born within molecular clouds known as stellar nurseries. The stars formed within such a cloud compose open clusters containing dozens to thousands of members. These clusters dissociate over time. Stars that separate themselves from the cluster's core are designated as members of the cluster's stellar association. If the remnant later drifts through the Milky Way as a coherent assemblage, then it is termed a moving group.