CHAPTER 6 THE CELESTIAL SPHERE
... or how it is defined, but we shall later learn that it is not quite fixed on the equator, but it moves slightly in a manner that I shall have to describe in due course. Thus the entire system of equatorial coordinates, and the right ascensions and declinations of the stars, depends on where this mys ...
... or how it is defined, but we shall later learn that it is not quite fixed on the equator, but it moves slightly in a manner that I shall have to describe in due course. Thus the entire system of equatorial coordinates, and the right ascensions and declinations of the stars, depends on where this mys ...
THE SHAPES OF ATOMIC LINES FROM THE SURFACES OF
... The profile of a spectral line formed at the stellar surface carries the imprint of several physical effects. Here we consider (1) magnetic (Zeeman or Paschen-Back) splitting by the star’s magnetic field, (2) longitudinal and transverse Doppler shifts, (3) special relativistic beaming, (4) gravitati ...
... The profile of a spectral line formed at the stellar surface carries the imprint of several physical effects. Here we consider (1) magnetic (Zeeman or Paschen-Back) splitting by the star’s magnetic field, (2) longitudinal and transverse Doppler shifts, (3) special relativistic beaming, (4) gravitati ...
Cosmology with GMRT
... Radio spectral lines from redshifted absorbers provide very competitive constraints on the cosmic variation of fundamental constants – Can be applied to a single object – Are not subject to the same systematics as optical lines – Probe a complementary redshift range ...
... Radio spectral lines from redshifted absorbers provide very competitive constraints on the cosmic variation of fundamental constants – Can be applied to a single object – Are not subject to the same systematics as optical lines – Probe a complementary redshift range ...
Evolution and nucleosynthesis of extremely metal
... basis of the information on the temperature, density, and convective velocities provided by the stellar structure model (see Paper I and references therein for details). The equations that describe the changes in the abundances are solved using an implicit method so that a large matrix of n2 is solv ...
... basis of the information on the temperature, density, and convective velocities provided by the stellar structure model (see Paper I and references therein for details). The equations that describe the changes in the abundances are solved using an implicit method so that a large matrix of n2 is solv ...
- StealthSkater
... forgotten material and can result in unusual accuracy. She made 2 erasures showing her conscious mind took control part of the time. "Betty described the map as 3-dimensional -- like looking through a window. The stars were tinted and glowed. The map material was flat and thin (not a model). And the ...
... forgotten material and can result in unusual accuracy. She made 2 erasures showing her conscious mind took control part of the time. "Betty described the map as 3-dimensional -- like looking through a window. The stars were tinted and glowed. The map material was flat and thin (not a model). And the ...
Stellar astrophysics based on interferometry
... • Intensity profiles change with time (pulsation, variable features, etc.). • Distance is often not well known (absolute radii). ...
... • Intensity profiles change with time (pulsation, variable features, etc.). • Distance is often not well known (absolute radii). ...
Stellarium – a valuable resource for teaching astronomy in the
... and heavenly coordinate systems are brought together in celestial navigation – the technique used by the ancient mariners to sail across the oceans. In Stellarium whenever a point on the sky is clicked, the celestial coordinates appear in the top left hand corner. To explore this feature it is best ...
... and heavenly coordinate systems are brought together in celestial navigation – the technique used by the ancient mariners to sail across the oceans. In Stellarium whenever a point on the sky is clicked, the celestial coordinates appear in the top left hand corner. To explore this feature it is best ...
High ions towards white dwarfs: circumstellar line shifts and stellar
... Absorption lines of several ions at various ionization stages are detected, and we investigate their origin by means of their kinematical properties, in combination with previous measurements with the FUSE satellite. We supplement with these new results a large set of archival white dwarfs UV data a ...
... Absorption lines of several ions at various ionization stages are detected, and we investigate their origin by means of their kinematical properties, in combination with previous measurements with the FUSE satellite. We supplement with these new results a large set of archival white dwarfs UV data a ...
FIRST STELLAR ABUNDANCES IN THE DWARF IRREGULAR
... 2003 within the same constraints as given for SexA-754 before. The candidate stars SexA-513, SexA-983, and SexA1456 on the other hand were found to be not suited for our abundances analyses which are tailored for A supergiants of a narrow temperature and luminosity range and the three stars had to b ...
... 2003 within the same constraints as given for SexA-754 before. The candidate stars SexA-513, SexA-983, and SexA1456 on the other hand were found to be not suited for our abundances analyses which are tailored for A supergiants of a narrow temperature and luminosity range and the three stars had to b ...
Universe 8e Lecture Chapter 24 Galaxies
... Distance to Galaxies: Standard candles, such as Cepheid variables and the most luminous supergiants, globular clusters, H II regions, and supernovae in a galaxy, are used in estimating intergalactic distances. The Tully-Fisher relation, which correlates the width of the 21-cm line of hydrogen in a s ...
... Distance to Galaxies: Standard candles, such as Cepheid variables and the most luminous supergiants, globular clusters, H II regions, and supernovae in a galaxy, are used in estimating intergalactic distances. The Tully-Fisher relation, which correlates the width of the 21-cm line of hydrogen in a s ...
McDonald I....Tisserand, P. et al ExELS an
... the Sun, and direct imaging is only effective within a few tens of parsecs. Statistical studies are therefore limited by systematic variation of parameters such as host star metallicity and age, and are limited by the small number of planets detected at large radii from their hosts. ...
... the Sun, and direct imaging is only effective within a few tens of parsecs. Statistical studies are therefore limited by systematic variation of parameters such as host star metallicity and age, and are limited by the small number of planets detected at large radii from their hosts. ...
3. Chapter 12
... Hubble’s observations of galaxies moving away from each other led astronomers to think about tracing the paths of the movement backward. Imagine you have a video of runners in a marathon that you decide to play backward. You would be able to see how all the runners—spread out as they near the finish ...
... Hubble’s observations of galaxies moving away from each other led astronomers to think about tracing the paths of the movement backward. Imagine you have a video of runners in a marathon that you decide to play backward. You would be able to see how all the runners—spread out as they near the finish ...
Document
... The Compton Gamma Ray Observatory produced maps of the steady gamma rays (see figure, below), most of which come from collisions between cosmic rays (see our discussion in Section 13.2f ) and atomic nuclei in clouds of gas. ...
... The Compton Gamma Ray Observatory produced maps of the steady gamma rays (see figure, below), most of which come from collisions between cosmic rays (see our discussion in Section 13.2f ) and atomic nuclei in clouds of gas. ...
CHERENKOV TELESCOPE ARRAY Dainis Dravins OPTIMIZING THE FOR INTENSITY INTERFEROMETRY
... Concordia station is visible in the distance. ...
... Concordia station is visible in the distance. ...
Infrared Properties of Star-Forming Dwarf Galaxies. I. Dwarf Irregular
... A sample of 34 dwarf irregular galaxies (dIs) in the Local Volume, most nearer than 5 Mpc, has been imaged in the near-infrared (NIR) in J and Ks at the Canada-France-Hawaii Telescope (CFHT) in Hawaii and the Observatorio Astronómico Nacional in the Sierra San Pedro Mártir, in Mexico. Absolute mag ...
... A sample of 34 dwarf irregular galaxies (dIs) in the Local Volume, most nearer than 5 Mpc, has been imaged in the near-infrared (NIR) in J and Ks at the Canada-France-Hawaii Telescope (CFHT) in Hawaii and the Observatorio Astronómico Nacional in the Sierra San Pedro Mártir, in Mexico. Absolute mag ...
THE ORION CONSTELLATION the Great Hunter
... about the process of how stars and planetary systems are formed from collapsing clouds of gas and dust. Astronomers have directly observed protoplanetary disks, brown dwarfs, intense and turbulent motions of the gas, and the photo-ionizing effects of massive nearby stars in the nebula. The Horsehead ...
... about the process of how stars and planetary systems are formed from collapsing clouds of gas and dust. Astronomers have directly observed protoplanetary disks, brown dwarfs, intense and turbulent motions of the gas, and the photo-ionizing effects of massive nearby stars in the nebula. The Horsehead ...
Darwin – A Mission to Detect, and Search for Life on, Extrasolar
... civilizations. Some of these assessments are based on the Drake equation. Unfortunately, they are only educated guesses, not because the equation per se is incorrect, but rather because nearly all of its factors are essentially undetermined due to the lack of observational tests. Thus, the basic que ...
... civilizations. Some of these assessments are based on the Drake equation. Unfortunately, they are only educated guesses, not because the equation per se is incorrect, but rather because nearly all of its factors are essentially undetermined due to the lack of observational tests. Thus, the basic que ...
The CCD Photometric Calibration Cookbook
... independent of each other and you can use just the ones appropriate for your purposes. It is also worth noting that astronomical photometry is a diverse subject. There are many different ways of making and reducing photometric observations. Observations can be made for very different types of progra ...
... independent of each other and you can use just the ones appropriate for your purposes. It is also worth noting that astronomical photometry is a diverse subject. There are many different ways of making and reducing photometric observations. Observations can be made for very different types of progra ...
MASSIVE CLOSE BINARIES
... that Case B is the more frequent class of interacting binaries. Compared to Case B, it is trivial to understand that Case A components have smaller final masses whereas it is obvious that Case C (and non-interacting) binaries are similar to single stars. Equation 1 decides upon the mass loss during ...
... that Case B is the more frequent class of interacting binaries. Compared to Case B, it is trivial to understand that Case A components have smaller final masses whereas it is obvious that Case C (and non-interacting) binaries are similar to single stars. Equation 1 decides upon the mass loss during ...
Today in Astronomy 102: black hole observations, v.2
... It is bright at infrared and radio wavelengths, and hard (shortwavelength) X rays, which are transmitted through the dust. The name Sagittarius A indicates that it’s the brightest radio source in the constellation Sagittarius (abbreviated Sgr). In fact, it was also the first extraterrestrial obj ...
... It is bright at infrared and radio wavelengths, and hard (shortwavelength) X rays, which are transmitted through the dust. The name Sagittarius A indicates that it’s the brightest radio source in the constellation Sagittarius (abbreviated Sgr). In fact, it was also the first extraterrestrial obj ...
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.