Prospects for Viewing Comet ISON
... comet's coma or head is spread out. So a comet with the same magnitude as a star appears fainter than a star of the same brightness because it's surface brightness per square arc second is so much less. Take a star out of focus in a telescope and see how big you can get a faint star before it disapp ...
... comet's coma or head is spread out. So a comet with the same magnitude as a star appears fainter than a star of the same brightness because it's surface brightness per square arc second is so much less. Take a star out of focus in a telescope and see how big you can get a faint star before it disapp ...
LIGO I - Indico
... GWs aren’t just a new band, they’re a new spectrum, with very different and complementary properties to EM waves. • Vibrations of space-time, not in space-time • Emitted by coherent motion of huge masses moving at near light-speed; not vibrations of electrons in atoms • Can’t be absorbed, scattered, ...
... GWs aren’t just a new band, they’re a new spectrum, with very different and complementary properties to EM waves. • Vibrations of space-time, not in space-time • Emitted by coherent motion of huge masses moving at near light-speed; not vibrations of electrons in atoms • Can’t be absorbed, scattered, ...
OBSERVATIONS OF PHYSICAL PROCESSES IN
... a velocity gradient across the central Hα region, suggesting the galaxy is getting pulled into or out of the cluster. The weak sloshing as well as the limit on X-ray cavities suggests we may be observing RXJ 2014.8-2430 during a rare period where sloshing and the AGN are beginning to heat the cluste ...
... a velocity gradient across the central Hα region, suggesting the galaxy is getting pulled into or out of the cluster. The weak sloshing as well as the limit on X-ray cavities suggests we may be observing RXJ 2014.8-2430 during a rare period where sloshing and the AGN are beginning to heat the cluste ...
Sample pages 1 PDF
... nuclear physics is occurring. Therefore, most AGB stars are classified as M, R, N or S, designations that have mostly been replaced by a collective term C, or “carbon stars.” Such stars have an abundance of carbon or oxygen in their photospheres, as there is an exchange of material between the core a ...
... nuclear physics is occurring. Therefore, most AGB stars are classified as M, R, N or S, designations that have mostly been replaced by a collective term C, or “carbon stars.” Such stars have an abundance of carbon or oxygen in their photospheres, as there is an exchange of material between the core a ...
FOSS Sun, Moon, and Planets Module Glossary 3 Edition © 2012
... gibbous Moon the shape of the Moon when it appears to be more than a quarter but not yet full and when it is less than full but not quite a third quarter. (SRB, IG) gravitational attraction the mutual force pulling together all objects that have mass (SRB) gravity the force of attraction between two ...
... gibbous Moon the shape of the Moon when it appears to be more than a quarter but not yet full and when it is less than full but not quite a third quarter. (SRB, IG) gravitational attraction the mutual force pulling together all objects that have mass (SRB) gravity the force of attraction between two ...
Abstract book
... rapid dynamical evolution once the cores collapsed. To this aim, we have analyzed the population of dense cores in the Pipe cold molecular cloud, based on the catalogue tailored by Román-Zuñiga and collaborators. Mass-Core Function (MCF) and Density-Core Function (DCF) can be very well represented b ...
... rapid dynamical evolution once the cores collapsed. To this aim, we have analyzed the population of dense cores in the Pipe cold molecular cloud, based on the catalogue tailored by Román-Zuñiga and collaborators. Mass-Core Function (MCF) and Density-Core Function (DCF) can be very well represented b ...
Lokal fulltext - Chalmers Publication Library
... in 1984 at Vega (α Lyrae, spectral class A0 V) by Aumann et al. (1984) with IRAS (Infrared Astronomical Satellite). However, as they saw the dust emission only in the spectral energy distribution (SED) they could not infer any shape. The excess is beyond 12 µm and peaks close to 60 µm. They interpre ...
... in 1984 at Vega (α Lyrae, spectral class A0 V) by Aumann et al. (1984) with IRAS (Infrared Astronomical Satellite). However, as they saw the dust emission only in the spectral energy distribution (SED) they could not infer any shape. The excess is beyond 12 µm and peaks close to 60 µm. They interpre ...
the stebbins galaxy: the origins of interstellar medium studies
... 1) The distribution of globular clusters, presumed to be centered around the center of mass of the Galaxy, shows the Sun to be far from that center. 2) The measured distances to globular clusters show the Galaxy to be about 70,000 parsecs (200,000 light-years or so) in diameter (Shapley, 1930a: 221) ...
... 1) The distribution of globular clusters, presumed to be centered around the center of mass of the Galaxy, shows the Sun to be far from that center. 2) The measured distances to globular clusters show the Galaxy to be about 70,000 parsecs (200,000 light-years or so) in diameter (Shapley, 1930a: 221) ...
IAA Annual Report 2014
... Research in extragalactic astronomy at the IAA is focused on two broad avenues: structure and evolution of galaxies, and quantum and classic gravity. Galaxies are the main focus of study from three different perspectives: (i) by themselves, understanding their dynamics, insterstellar medium, and evo ...
... Research in extragalactic astronomy at the IAA is focused on two broad avenues: structure and evolution of galaxies, and quantum and classic gravity. Galaxies are the main focus of study from three different perspectives: (i) by themselves, understanding their dynamics, insterstellar medium, and evo ...
solar system
... Sun, and a conical motion of its axis of rotation. This last motion was made necessary because Copernicus conceptualized the Earth's annual motion as the result of the Earth being embedded in a spherical shell centered on the Sun. Its axis of rotation therefore did not remain parallel to itself with ...
... Sun, and a conical motion of its axis of rotation. This last motion was made necessary because Copernicus conceptualized the Earth's annual motion as the result of the Earth being embedded in a spherical shell centered on the Sun. Its axis of rotation therefore did not remain parallel to itself with ...
The Perseid Meteor Shower
... from a meteor. Comets are balls of ice that orbit around the sun. Sometimes comets are called "dirty snowballs" because they are icy and mixed with bits of rock and dust. When comets come close to the warm Sun some of the dusty ice changes into dusty gas. The gas and the dust form a tail that we ca ...
... from a meteor. Comets are balls of ice that orbit around the sun. Sometimes comets are called "dirty snowballs" because they are icy and mixed with bits of rock and dust. When comets come close to the warm Sun some of the dusty ice changes into dusty gas. The gas and the dust form a tail that we ca ...
Observational Studies of Interacting Galaxies and the Development
... expected value. Spectroscopically, the kinematic properties of close pair galaxies were studied to understand how star formation were quenched at z ∼ 0.5. I discovered that the number of red-red pairs are rare, which does not support the gravitational quenching mechanism suggested by the hot halo mo ...
... expected value. Spectroscopically, the kinematic properties of close pair galaxies were studied to understand how star formation were quenched at z ∼ 0.5. I discovered that the number of red-red pairs are rare, which does not support the gravitational quenching mechanism suggested by the hot halo mo ...
magazine
... he Very Large Telescope array (VLT) is operated by the European Southern Observatory (ESO) and is located on Cerro Paranal in a remote region of the Atacama desert in Chile; see Figure 1. The VLT is the world’s most advanced optical astronomical observatory, consisting of four Unit Telescopes with m ...
... he Very Large Telescope array (VLT) is operated by the European Southern Observatory (ESO) and is located on Cerro Paranal in a remote region of the Atacama desert in Chile; see Figure 1. The VLT is the world’s most advanced optical astronomical observatory, consisting of four Unit Telescopes with m ...
File
... astrologers claim they can at least predict which astrological signs will be compatible or incompatible when it comes to personal relationships. Silverman compared such predictions to the actual records and found no correlations. For example “incompatibly signed” men and women got married as frequen ...
... astrologers claim they can at least predict which astrological signs will be compatible or incompatible when it comes to personal relationships. Silverman compared such predictions to the actual records and found no correlations. For example “incompatibly signed” men and women got married as frequen ...
Astronomy Astrophysics Detailed abundances of a large sample of giant stars in... and in the Sagittarius nucleus
... ejecta of massive stars early in their lifetime. In turn, this is most likely related to their formation mechanisms (e.g. Carretta 2006) and the environment in which they formed (Carretta et al. 2010a). In addition to earlier studies (see Kraft 1994, for references), our completed survey of 19 GCs ( ...
... ejecta of massive stars early in their lifetime. In turn, this is most likely related to their formation mechanisms (e.g. Carretta 2006) and the environment in which they formed (Carretta et al. 2010a). In addition to earlier studies (see Kraft 1994, for references), our completed survey of 19 GCs ( ...
Galactic Nebulae
... Runaway star . Xi Persei is an O/B type giant and has has been Ejected from the Perseus OB2 stellar association over 400,000 Years ago . It encountered NGC1499 about 100,000 years ago Nebula is about 1100 light years away , and has a low surface Brightness – difficult to see visually Discovered by B ...
... Runaway star . Xi Persei is an O/B type giant and has has been Ejected from the Perseus OB2 stellar association over 400,000 Years ago . It encountered NGC1499 about 100,000 years ago Nebula is about 1100 light years away , and has a low surface Brightness – difficult to see visually Discovered by B ...
Cosmos
... matter in the universe eventually to stop the recession of distant galaxies, and whether the universe is infinitely old and therefore uncreated. Some light on both these questions may since have been cast in experiments by Frederick Reines, of the University of California, who believes he has discov ...
... matter in the universe eventually to stop the recession of distant galaxies, and whether the universe is infinitely old and therefore uncreated. Some light on both these questions may since have been cast in experiments by Frederick Reines, of the University of California, who believes he has discov ...
FY96
... The emission region is very complex, with four expanding shells identified. One is probably asymmetric because of its encounter with an associated molecular cloud; the largest expansion velocity is over 100 km/s. With densities derived from emission line diagnostics and accurate velocity maps, the k ...
... The emission region is very complex, with four expanding shells identified. One is probably asymmetric because of its encounter with an associated molecular cloud; the largest expansion velocity is over 100 km/s. With densities derived from emission line diagnostics and accurate velocity maps, the k ...
Observational astronomy
Observational astronomy is a division of the astronomical science that is concerned with recording data, in contrast with theoretical astrophysics, which is mainly concerned with finding out the measurable implications of physical models. It is the practice of observing celestial objects by using telescopes and other astronomical apparatus.As a science, the study of astronomy is somewhat hindered in that direct experiments with the properties of the distant universe are not possible. However, this is partly compensated by the fact that astronomers have a vast number of visible examples of stellar phenomena that can be examined. This allows for observational data to be plotted on graphs, and general trends recorded. Nearby examples of specific phenomena, such as variable stars, can then be used to infer the behavior of more distant representatives. Those distant yardsticks can then be employed to measure other phenomena in that neighborhood, including the distance to a galaxy.Galileo Galilei turned a telescope to the heavens and recorded what he saw. Since that time, observational astronomy has made steady advances with each improvement in telescope technology.A traditional division of observational astronomy is given by the region of the electromagnetic spectrum observed: Optical astronomy is the part of astronomy that uses optical components (mirrors, lenses and solid-state detectors) to observe light from near infrared to near ultraviolet wavelengths. Visible-light astronomy (using wavelengths that can be detected with the eyes, about 400 - 700 nm) falls in the middle of this range. Infrared astronomy deals with the detection and analysis of infrared radiation (this typically refers to wavelengths longer than the detection limit of silicon solid-state detectors, about 1 μm wavelength). The most common tool is the reflecting telescope but with a detector sensitive to infrared wavelengths. Space telescopes are used at certain wavelengths where the atmosphere is opaque, or to eliminate noise (thermal radiation from the atmosphere). Radio astronomy detects radiation of millimetre to dekametre wavelength. The receivers are similar to those used in radio broadcast transmission but much more sensitive. See also Radio telescopes. High-energy astronomy includes X-ray astronomy, gamma-ray astronomy, and extreme UV astronomy, as well as studies of neutrinos and cosmic rays.Optical and radio astronomy can be performed with ground-based observatories, because the atmosphere is relatively transparent at the wavelengths being detected. Observatories are usually located at high altitudes so as to minimise the absorption and distortion caused by the Earth's atmosphere. Some wavelengths of infrared light are heavily absorbed by water vapor, so many infrared observatories are located in dry places at high altitude, or in space.The atmosphere is opaque at the wavelengths used by X-ray astronomy, gamma-ray astronomy, UV astronomy and (except for a few wavelength ""windows"") far infrared astronomy, so observations must be carried out mostly from balloons or space observatories. Powerful gamma rays can, however be detected by the large air showers they produce, and the study of cosmic rays is a rapidly expanding branch of astronomy.For much of the history of observational astronomy, almost all observation was performed in the visual spectrum with optical telescopes. While the Earth's atmosphere is relatively transparent in this portion of the electromagnetic spectrum, most telescope work is still dependent on seeing conditions and air transparency, and is generally restricted to the night time. The seeing conditions depend on the turbulence and thermal variations in the air. Locations that are frequently cloudy or suffer from atmospheric turbulence limit the resolution of observations. Likewise the presence of the full Moon can brighten up the sky with scattered light, hindering observation of faint objects.For observation purposes, the optimal location for an optical telescope is undoubtedly in outer space. There the telescope can make observations without being affected by the atmosphere. However, at present it remains costly to lift telescopes into orbit. Thus the next best locations are certain mountain peaks that have a high number of cloudless days and generally possess good atmospheric conditions (with good seeing conditions). The peaks of the islands of Mauna Kea, Hawaii and La Palma possess these properties, as to a lesser extent do inland sites such as Llano de Chajnantor, Paranal, Cerro Tololo and La Silla in Chile. These observatory locations have attracted an assemblage of powerful telescopes, totalling many billion US dollars of investment.The darkness of the night sky is an important factor in optical astronomy. With the size of cities and human populated areas ever expanding, the amount of artificial light at night has also increased. These artificial lights produce a diffuse background illumination that makes observation of faint astronomical features very difficult without special filters. In a few locations such as the state of Arizona and in the United Kingdom, this has led to campaigns for the reduction of light pollution. The use of hoods around street lights not only improves the amount of light directed toward the ground, but also helps reduce the light directed toward the sky.Atmospheric effects (astronomical seeing) can severely hinder the resolution of a telescope. Without some means of correcting for the blurring effect of the shifting atmosphere, telescopes larger than about 15–20 cm in aperture can not achieve their theoretical resolution at visible wavelengths. As a result, the primary benefit of using very large telescopes has been the improved light-gathering capability, allowing very faint magnitudes to be observed. However the resolution handicap has begun to be overcome by adaptive optics, speckle imaging and interferometric imaging, as well as the use of space telescopes.Astronomers have a number of observational tools that they can use to make measurements of the heavens. For objects that are relatively close to the Sun and Earth, direct and very precise position measurements can be made against a more distant (and thereby nearly stationary) background. Early observations of this nature were used to develop very precise orbital models of the various planets, and to determine their respective masses and gravitational perturbations. Such measurements led to the discovery of the planets Uranus, Neptune, and (indirectly) Pluto. They also resulted in an erroneous assumption of a fictional planet Vulcan within the orbit of Mercury (but the explanation of the precession of Mercury's orbit by Einstein is considered one of the triumphs of his general relativity theory).