SkyWatcher2017.5 1.3 Mb - Boise Astronomical Society
... 5/26 The Moon is at perigee, subtending 33' 27'' from a distance of 357,210 kilometers (221,958 miles), at 1:21; a double Galilean satellite shadow transit begins at 5:47; Mercury is at its greatest latitude south of the ecliptic plane (-7.0 degrees) at 20:00 5/27 Mars is 5.3 degrees north of the Mo ...
... 5/26 The Moon is at perigee, subtending 33' 27'' from a distance of 357,210 kilometers (221,958 miles), at 1:21; a double Galilean satellite shadow transit begins at 5:47; Mercury is at its greatest latitude south of the ecliptic plane (-7.0 degrees) at 20:00 5/27 Mars is 5.3 degrees north of the Mo ...
La Sapienza – 2015
... The effect is very small. For instance Jupiter induces a 12 m/s velocity change on the Sun for an extern observer whereas the Saturn effect is only 2.7 m/s. La Sapienza – 2015 ...
... The effect is very small. For instance Jupiter induces a 12 m/s velocity change on the Sun for an extern observer whereas the Saturn effect is only 2.7 m/s. La Sapienza – 2015 ...
SOHO`s Frequently Asked Questions
... The Sun is a star, it is just a lot closer than other stars, and the Earth and the other planets of our solar system are in orbit around it. The Sun is the ultimate source of almost all the energy on Earth. The Sun is Big. It is 1.3 million km (0.86 million miles) in diameter. 110 Earths strung toge ...
... The Sun is a star, it is just a lot closer than other stars, and the Earth and the other planets of our solar system are in orbit around it. The Sun is the ultimate source of almost all the energy on Earth. The Sun is Big. It is 1.3 million km (0.86 million miles) in diameter. 110 Earths strung toge ...
An Atlas of Stellar Spectra
... which the identification can be made from the features available; but good judgment is necessary in any case, whether the decision is made from the general appearance or from more objective measures. The problem of a classification according to luminosity is a difficult one. In the first place, line ...
... which the identification can be made from the features available; but good judgment is necessary in any case, whether the decision is made from the general appearance or from more objective measures. The problem of a classification according to luminosity is a difficult one. In the first place, line ...
Galaxy Assembly through Mergers
... of star formation to severe morphological changes. On the other hand, for mergers between elliptical, gas-poor galaxies, the apparent absence of strong perturbations poses another challenge, even though, given their massive nature, they may be responsible for the high mass end of the mass function. ...
... of star formation to severe morphological changes. On the other hand, for mergers between elliptical, gas-poor galaxies, the apparent absence of strong perturbations poses another challenge, even though, given their massive nature, they may be responsible for the high mass end of the mass function. ...
my dissertation (PhD. Thesis) - Argelander
... To gain access to information about galaxies one has an enormous amount of objects at hand, galaxies of all sizes and distances ranging from our “backyard”, namely the Milky Way itself and the Local Group to galaxies at a redshift of z ' 11 and higher. Each approach can deliver different information ...
... To gain access to information about galaxies one has an enormous amount of objects at hand, galaxies of all sizes and distances ranging from our “backyard”, namely the Milky Way itself and the Local Group to galaxies at a redshift of z ' 11 and higher. Each approach can deliver different information ...
1 Globular Cluster Systems - McMaster Physics and Astronomy
... Sun in the outer halo of the Milky Way. The picture shown is an I band image taken with the Canada-France-Hawaii Telescope (see Harris et al. 1997c). The eld size is 4.6 arcmin (or 33 parsecs) across and the image resolution (\seeing") is 0.5 arcsec. Right panel: A globular cluster in the halo of t ...
... Sun in the outer halo of the Milky Way. The picture shown is an I band image taken with the Canada-France-Hawaii Telescope (see Harris et al. 1997c). The eld size is 4.6 arcmin (or 33 parsecs) across and the image resolution (\seeing") is 0.5 arcsec. Right panel: A globular cluster in the halo of t ...
The physics of line-driven winds of hot massive stars
... stellar winds. They create large bubbles around the stars by sweeping up the interstellar gas that is encountered (see Figure 1.2). Through these stellar winds, massive stars lose mass. This may severely affect their course of evolution – i.e. the way in which they change their physical state over t ...
... stellar winds. They create large bubbles around the stars by sweeping up the interstellar gas that is encountered (see Figure 1.2). Through these stellar winds, massive stars lose mass. This may severely affect their course of evolution – i.e. the way in which they change their physical state over t ...
The evolution of low-metallicity massive stars - Argelander
... a measure of the distance of a given object from us. The larger the redshift, the more distant (and the older) the object. Hence the term high-redshift Universe refers to the early Universe. Another aspect of observing the early Universe is that one needs very efficient, highlyresolving telescopes, ...
... a measure of the distance of a given object from us. The larger the redshift, the more distant (and the older) the object. Hence the term high-redshift Universe refers to the early Universe. Another aspect of observing the early Universe is that one needs very efficient, highlyresolving telescopes, ...
Zweijahresbericht 2000-2001
... by Günther’s moving spirit – and impressive work load (7 days a week at all geographic longitudes!) – now came to an end. We all would like to use this public place to express our sincerest thanks for his outstanding and hearty engagement for the institute and astronomy in general. A year earlier, ...
... by Günther’s moving spirit – and impressive work load (7 days a week at all geographic longitudes!) – now came to an end. We all would like to use this public place to express our sincerest thanks for his outstanding and hearty engagement for the institute and astronomy in general. A year earlier, ...
1997 Apparition of Comet Hale-Bopp - HIGP
... Historical Comet Observations. Comets have been the most feared celestial objects in history because of their sudden and sometimes bright appearance. When near the sun, comets can be the largest objects in the Solar System. To ancient peoples, they were interpreted as ill omens of impending disaster ...
... Historical Comet Observations. Comets have been the most feared celestial objects in history because of their sudden and sometimes bright appearance. When near the sun, comets can be the largest objects in the Solar System. To ancient peoples, they were interpreted as ill omens of impending disaster ...
A Brief Overview of the History of Western Astrology
... tablets, and the Venus Tablet of Amisaduqa. The Enuma Anu Enlil dates from the 8th century BC and contains older material such as the Venus Tablet, which is thought to have been written during the reign of the Babylonian king, Amisaduqa, c 1600 BC. In its earliest stages, Mesopotamian astrology was ...
... tablets, and the Venus Tablet of Amisaduqa. The Enuma Anu Enlil dates from the 8th century BC and contains older material such as the Venus Tablet, which is thought to have been written during the reign of the Babylonian king, Amisaduqa, c 1600 BC. In its earliest stages, Mesopotamian astrology was ...
Characterization of the physical properties of the ROSETTA target
... This thesis is based on the analysis and interpretation of photometric and spectroscopic observations of the Jupiter family comet (JFC) 67P/Churyumov-Gerasimenko (67P/C-G) at large heliocentric distance. The aim of this study is to provide a good characterization of the nucleus of the ROSETTA target ...
... This thesis is based on the analysis and interpretation of photometric and spectroscopic observations of the Jupiter family comet (JFC) 67P/Churyumov-Gerasimenko (67P/C-G) at large heliocentric distance. The aim of this study is to provide a good characterization of the nucleus of the ROSETTA target ...
MERCURY In-flight calibration of the PHEBUS UV instrument and
... To prepare for in-flight and orbit spectral calibrations, a set of reference stars is determined and evaluated to match the resolution and spectral range of the detector. Predictions on the possibility of detection of a wide range of emission lines in space and in Mercury’s exosphere are given (scie ...
... To prepare for in-flight and orbit spectral calibrations, a set of reference stars is determined and evaluated to match the resolution and spectral range of the detector. Predictions on the possibility of detection of a wide range of emission lines in space and in Mercury’s exosphere are given (scie ...
IOTA Observer`s Manual
... discovery of its ring system. This ring system might actually have been seen indirectly by the discoverer of Uranus, William Herschel, as he noticed faint stars dim as the planet passed close by. Occultation observations are fun to observe. There is perhaps nothing more exciting than watching a star ...
... discovery of its ring system. This ring system might actually have been seen indirectly by the discoverer of Uranus, William Herschel, as he noticed faint stars dim as the planet passed close by. Occultation observations are fun to observe. There is perhaps nothing more exciting than watching a star ...
PhD thesis
... 3.3 Continuum results . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3.1 Centimeter and millimeter continuum results . . . . . . . . . 3.3.2 Spectral energy distribution . . . . . . . . . . . . . . . . . . . 3.4 Molecular results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 ...
... 3.3 Continuum results . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3.1 Centimeter and millimeter continuum results . . . . . . . . . 3.3.2 Spectral energy distribution . . . . . . . . . . . . . . . . . . . 3.4 Molecular results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 ...
Worlds Beyond The Poles
... This is reality; it is truth stranger than any fiction the world has known: There is no physical end to the Earth’s northern and southern extent. The Earth merges with land areas of the universe about us that exist straight ahead beyond the North Pole and the South Pole “points” of theory. It is now ...
... This is reality; it is truth stranger than any fiction the world has known: There is no physical end to the Earth’s northern and southern extent. The Earth merges with land areas of the universe about us that exist straight ahead beyond the North Pole and the South Pole “points” of theory. It is now ...
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).