maximum likelihood fitting of tidal streams with application
... SDSS has been expanded to include a new project, SEGUE. This extension will eventually include 3500 deg2 of new imaging data which is collected in 2.5 wide great circles on the sky, but these great circles do not in general match those laid out on the sky for the SDSS, and they are not adjacent to ...
... SDSS has been expanded to include a new project, SEGUE. This extension will eventually include 3500 deg2 of new imaging data which is collected in 2.5 wide great circles on the sky, but these great circles do not in general match those laid out on the sky for the SDSS, and they are not adjacent to ...
The Age Distribution of Potential Intelligent Life in the Milky Way
... complex life (Gowanlock et al. 2011) and has been predicted to be an annular region which widens with time (Lineweaver et al. 2004). However, Prantzos (2008) found that almost all of the Galaxy’s disk may contain habitable planets at present, therefore the necessity for a GHZ is less motivated. The ...
... complex life (Gowanlock et al. 2011) and has been predicted to be an annular region which widens with time (Lineweaver et al. 2004). However, Prantzos (2008) found that almost all of the Galaxy’s disk may contain habitable planets at present, therefore the necessity for a GHZ is less motivated. The ...
VY Canis Majoris: The Astrophysical Basis of Its Luminosity
... photosphere or its surface directly. It has been known for some time that VY CMa’s absorption spectrum is significantly redshifted with respect to its systemic velocity (Humphreys 1975, Wallerstein 1977) due to scattering by dust (Herbig 1970, Kwok 1976, Van Blerkom & Van Blerkom 1978). Indeed, most ...
... photosphere or its surface directly. It has been known for some time that VY CMa’s absorption spectrum is significantly redshifted with respect to its systemic velocity (Humphreys 1975, Wallerstein 1977) due to scattering by dust (Herbig 1970, Kwok 1976, Van Blerkom & Van Blerkom 1978). Indeed, most ...
The low-mass dispersed population around the Lupus clouds
... The spectral region covered by our observations is well suited for the classification of stars in the range of temperatures expected from the spectral energy distribution fits carried out by CSL (T eff . 3700 K in Lupus 1, T eff . 3400 K in Lupus 3 and 4), providing diagnostic features of temperatur ...
... The spectral region covered by our observations is well suited for the classification of stars in the range of temperatures expected from the spectral energy distribution fits carried out by CSL (T eff . 3700 K in Lupus 1, T eff . 3400 K in Lupus 3 and 4), providing diagnostic features of temperatur ...
Spectropolarimetry of the massive post
... Here, we address the issue by investigating the circumstellar ejecta of two yellow hypergiants, IRC +10420 and HD 179821. These objects are thought to have evolved off the post-Red Supergiant branch and are still surrounded by mass ejected during a previous mass losing phase. Only a few yellow hyper ...
... Here, we address the issue by investigating the circumstellar ejecta of two yellow hypergiants, IRC +10420 and HD 179821. These objects are thought to have evolved off the post-Red Supergiant branch and are still surrounded by mass ejected during a previous mass losing phase. Only a few yellow hyper ...
Supernovae - University of Texas Astronomy Home Page
... heavens favored Kepler in his turn with the explosion of a supernova in 1604. Kepler also took careful data by which we deduce that he witnessed the same kind of explosion as his master. Although there are counterarguments and some controversy, both Tycho's and Kepler's supernovae are widely regard ...
... heavens favored Kepler in his turn with the explosion of a supernova in 1604. Kepler also took careful data by which we deduce that he witnessed the same kind of explosion as his master. Although there are counterarguments and some controversy, both Tycho's and Kepler's supernovae are widely regard ...
Minimum Distance Estimation of Milky Way
... the said densities is the realization obtained from the model parameter value that corresponds best to the true value; the “true” value of the model parameter indicates the value which suitably describes the observations. Maximization of the affinity in this context is equivalent to the minimization ...
... the said densities is the realization obtained from the model parameter value that corresponds best to the true value; the “true” value of the model parameter indicates the value which suitably describes the observations. Maximization of the affinity in this context is equivalent to the minimization ...
francesco ingoli`s essay to galileo: tycho brahe
... idea some months earlier in April 1615, stating in a letter that if solid evidence for the Copernican theory were found then the literal sense of scripture would have to give way to a different interpretation, but not until then. 10 This view seems to have been common in Jesuit circles, but the Fren ...
... idea some months earlier in April 1615, stating in a letter that if solid evidence for the Copernican theory were found then the literal sense of scripture would have to give way to a different interpretation, but not until then. 10 This view seems to have been common in Jesuit circles, but the Fren ...
Monday, Sept. 8 - University of Manitoba Physics Department
... The fraction of the outer circle covered by the diameter of the object is equal to the fraction of the inner circle covered by the angular ...
... The fraction of the outer circle covered by the diameter of the object is equal to the fraction of the inner circle covered by the angular ...
A Search for Extrasolar Planets Using Echoes Produced in Flare
... While radar uses a RF energy pulse, this method relies on a pulse of light emitted from the star. An implicit assumption is that the pulse of light propagates in all directions equally and simultaneously; that the pulse radiates isotropically. For the observer on Earth the pulse follows two paths: o ...
... While radar uses a RF energy pulse, this method relies on a pulse of light emitted from the star. An implicit assumption is that the pulse of light propagates in all directions equally and simultaneously; that the pulse radiates isotropically. For the observer on Earth the pulse follows two paths: o ...
Alignment Troubleshooting Alignment Procedure
... that is closest to your current observing site. The city you choose will be remembered in the hand controls memory so that it will be automatically displayed the next time an alignment is done. Alternatively, if you know the exact longitude and latitude of your observing site, it can be entered dire ...
... that is closest to your current observing site. The city you choose will be remembered in the hand controls memory so that it will be automatically displayed the next time an alignment is done. Alternatively, if you know the exact longitude and latitude of your observing site, it can be entered dire ...
Astronomers` Observing Guides
... significance in the cosmic scheme of things, and the valuable insights they provide into such fundamental matters as stellar masses and the ultimate fate of stars. The more we know about these fascinating objects, the more enjoyment we will ultimately derive from actually viewing them firsthand with b ...
... significance in the cosmic scheme of things, and the valuable insights they provide into such fundamental matters as stellar masses and the ultimate fate of stars. The more we know about these fascinating objects, the more enjoyment we will ultimately derive from actually viewing them firsthand with b ...
Effects of triple-α and C(α, γ )16 O reaction rates on the supernova
... Apart from appearances of observations, we can see the effects of the OKK rate on stellar evolution from the ignition properties. A helium core flash is triggered if the nuclear energy generation rates (εn ) become significantly larger than the neutrino energy loss rates (εν ). We can understand cle ...
... Apart from appearances of observations, we can see the effects of the OKK rate on stellar evolution from the ignition properties. A helium core flash is triggered if the nuclear energy generation rates (εn ) become significantly larger than the neutrino energy loss rates (εν ). We can understand cle ...
A Star - Cloudy Nights
... Double Star Two thirds of all stars in the sky have a companion star. These double stars, or binary star systems have two stars that orbit around a common point. Some double stars orbit each other very quickly (once every few hours), while some orbit each other very slowly (once every few thousand y ...
... Double Star Two thirds of all stars in the sky have a companion star. These double stars, or binary star systems have two stars that orbit around a common point. Some double stars orbit each other very quickly (once every few hours), while some orbit each other very slowly (once every few thousand y ...
The Secular and Rotational Brightness Variations of Neptune
... described by Hall and Genet (1988). (Extinction and color transformation are described later in this section.) Some of the magnitudes reported in the earlier papers lacked color transformations but all the data analyzed here have been transformed. Formal errors are not available for these observati ...
... described by Hall and Genet (1988). (Extinction and color transformation are described later in this section.) Some of the magnitudes reported in the earlier papers lacked color transformations but all the data analyzed here have been transformed. Formal errors are not available for these observati ...
Fast Facts - Canada France Hawaii Telescope
... With ESPaDOnS, the only high-resolution spectropolarimeter available on 4-m class or larger telescopes, astronomers can now observe with unprecedented details the magnetic field around stars, opening information on the physics of stars that was previously only available for our closest star, the Sun ...
... With ESPaDOnS, the only high-resolution spectropolarimeter available on 4-m class or larger telescopes, astronomers can now observe with unprecedented details the magnetic field around stars, opening information on the physics of stars that was previously only available for our closest star, the Sun ...
Word version - White dwarf stars and the Chandrasekhar limit
... Sommerfeld came to Presidency college to give a lecture. Chandra spoke to Sommerfeld after the lecture, and was informed that much of the physics he had learned had been changed by new developments due to Heisenberg, Dirac, Pauli, and others. Sommerfeld left Chandra with some unpublished material of ...
... Sommerfeld came to Presidency college to give a lecture. Chandra spoke to Sommerfeld after the lecture, and was informed that much of the physics he had learned had been changed by new developments due to Heisenberg, Dirac, Pauli, and others. Sommerfeld left Chandra with some unpublished material of ...
Hipparcos
Hipparcos was a scientific satellite of the European Space Agency (ESA), launched in 1989 and operated until 1993. It was the first space experiment devoted to precision astrometry, the accurate measurement of the positions of celestial objects on the sky. This permitted the accurate determination of proper motions and parallaxes of stars, allowing a determination of their distance and tangential velocity. When combined with radial-velocity measurements from spectroscopy, this pinpointed all six quantities needed to determine the motion of stars. The resulting Hipparcos Catalogue, a high-precision catalogue of more than 118,200 stars, was published in 1997. The lower-precision Tycho Catalogue of more than a million stars was published at the same time, while the enhanced Tycho-2 Catalogue of 2.5 million stars was published in 2000. Hipparcos ' follow-up mission, Gaia, was launched in 2013.The word ""Hipparcos"" is an acronym for High precision parallax collecting satellite and also a reference to the ancient Greek astronomer Hipparchus of Nicaea, who is noted for applications of trigonometry to astronomy and his discovery of the precession of the equinoxes.