ALMA Science Results
... – What is SgrA* exactly?? Accretion flow? Jet? SED appears partially self-absorbed synchrotron. Usually this type has a jet. – Measured time lag in radio emission. Some part of jet is optically thick at some frequency. High frequencies closer in, see those first. – ALMA maps of the mini spiral dynam ...
... – What is SgrA* exactly?? Accretion flow? Jet? SED appears partially self-absorbed synchrotron. Usually this type has a jet. – Measured time lag in radio emission. Some part of jet is optically thick at some frequency. High frequencies closer in, see those first. – ALMA maps of the mini spiral dynam ...
Chapter 13 Measuring the properties of stars
... What is the difference between spectroscopic and visual binaries? A. Spectroscopic binaries have double spectral lines but do not move. B. Visual binaries are pairs of stars in the same region in the sky but are not gravitationally interacting. C. A visual binary does not show changes in the spectr ...
... What is the difference between spectroscopic and visual binaries? A. Spectroscopic binaries have double spectral lines but do not move. B. Visual binaries are pairs of stars in the same region in the sky but are not gravitationally interacting. C. A visual binary does not show changes in the spectr ...
Unit 1 test review and answer key 16
... ____ 22. Radio telescopes reveal characteristics of celestial objects that cannot be studied using an optical telescope. ____ 23. A solar prominence is a large loop of slightly cooler gas that extends out from the Sun’s surface. ____ 24. A solar wind is a stream of high-energy particles. ____ 25. T ...
... ____ 22. Radio telescopes reveal characteristics of celestial objects that cannot be studied using an optical telescope. ____ 23. A solar prominence is a large loop of slightly cooler gas that extends out from the Sun’s surface. ____ 24. A solar wind is a stream of high-energy particles. ____ 25. T ...
Kepler Mission: The Search for Earth-sized Planets
... observer and a star and blocks a small amount of light from the star, causing the light from the star to dim slightly for a few hours. ...
... observer and a star and blocks a small amount of light from the star, causing the light from the star to dim slightly for a few hours. ...
Impact on stellar properties of changing physics SAC Summer
... the star settles at the stellar birthline (see Figure 3) in the Hertzsprung-Russell diagram. The pre-main-sequence evolutionary tracks for a sequence of masses are shown in Figure 2. As the protostar-collapse slows down, the star’s luminosity decreases enormously while its effective temperature incr ...
... the star settles at the stellar birthline (see Figure 3) in the Hertzsprung-Russell diagram. The pre-main-sequence evolutionary tracks for a sequence of masses are shown in Figure 2. As the protostar-collapse slows down, the star’s luminosity decreases enormously while its effective temperature incr ...
Digital Video Analysis Of Anomalous Space Objects
... A slight tail at the beginning of the track (Figure 9a) suggests that the object may be moving up and out of the atmosphere. This hypothesis is consistent with measurements of the M l ' s brightness. Figure 10 shows the brightness of MI at the point where it appears. Instead of changing abruptly as ...
... A slight tail at the beginning of the track (Figure 9a) suggests that the object may be moving up and out of the atmosphere. This hypothesis is consistent with measurements of the M l ' s brightness. Figure 10 shows the brightness of MI at the point where it appears. Instead of changing abruptly as ...
CH15.AST1001.F16.EDS
... Where will the gas be in 1 trillion years? A. Blown out of galaxy B. Still recycling just like now C. Locked into white dwarfs and low-mass stars ...
... Where will the gas be in 1 trillion years? A. Blown out of galaxy B. Still recycling just like now C. Locked into white dwarfs and low-mass stars ...
X-ray Astronomy and the search for Black Holes
... plasma, as also seen in magnetic and non-magnetic CVs • These symbiotic stars have harder spectra than non-magnetic CVs • Yet they are unlikely to have a magnetic white dwarf • Non-magnetic CVs can have high temperatures if the accreting white dwarf is massive - SS Cyg at ~1.1Msun is the hardest amo ...
... plasma, as also seen in magnetic and non-magnetic CVs • These symbiotic stars have harder spectra than non-magnetic CVs • Yet they are unlikely to have a magnetic white dwarf • Non-magnetic CVs can have high temperatures if the accreting white dwarf is massive - SS Cyg at ~1.1Msun is the hardest amo ...
XRaySNR_sm - Gettysburg College
... We note that the “observed spectra” used in this lab are actually models themselves, based on the physical parameters of the nebula found by Hwang and Laming. The actual spectral data from X-ray observatories are quite noisy and difficult to present, so this method was used instead. The spectra were ...
... We note that the “observed spectra” used in this lab are actually models themselves, based on the physical parameters of the nebula found by Hwang and Laming. The actual spectral data from X-ray observatories are quite noisy and difficult to present, so this method was used instead. The spectra were ...
PPT - University of Waterloo
... facility-class far-infrared/submm space observatory – 1/3 Guaranteed Time, 2/3 Open Time with annual calls for proposals ...
... facility-class far-infrared/submm space observatory – 1/3 Guaranteed Time, 2/3 Open Time with annual calls for proposals ...
Listening for Gravitational Waves (ppt version)
... Eddington, when the Sun was silhouetted against the Hyades star cluster Their measurements showed that the light from these stars was bent as it grazed the Sun, by the exact amount of Einstein's predictions. The light never changes course, but merely follows the curvature of space. Astronomers now r ...
... Eddington, when the Sun was silhouetted against the Hyades star cluster Their measurements showed that the light from these stars was bent as it grazed the Sun, by the exact amount of Einstein's predictions. The light never changes course, but merely follows the curvature of space. Astronomers now r ...
How to deal with the Equations in the homeworks
... one life or across many generations. Revelation is also strongly person-centric, meaning its goals are to provide knowledge for sentient being with “souls” to “show the way.” The purpose of a science of the natural world is not to address any form of revelation, insofar as revelation refrains from s ...
... one life or across many generations. Revelation is also strongly person-centric, meaning its goals are to provide knowledge for sentient being with “souls” to “show the way.” The purpose of a science of the natural world is not to address any form of revelation, insofar as revelation refrains from s ...
The Marine Sextant
... • A marine sextant is nothing more than a device designed to measure the angle between two objects with a great deal of precision. • In celestial navigation, these two objects are – a celestial body (star, sun, moon, or planet) – the visible horizon ...
... • A marine sextant is nothing more than a device designed to measure the angle between two objects with a great deal of precision. • In celestial navigation, these two objects are – a celestial body (star, sun, moon, or planet) – the visible horizon ...
Is $^ 6$ Li in metal-poor halo stars produced in situ by solar
... It has been known for many years that the chromospheric and coronal activities of dwarf stars are closely related to their rotation (Kraft 1967). This relationship results from the generation and amplification of surface magnetic fields by a complex dynamo mechanism, whose efficiency depends on the in ...
... It has been known for many years that the chromospheric and coronal activities of dwarf stars are closely related to their rotation (Kraft 1967). This relationship results from the generation and amplification of surface magnetic fields by a complex dynamo mechanism, whose efficiency depends on the in ...
Cataclysmic Cosmic Events and How to Observe Them www.springer.com/series/5338
... Moon and planets, as well as bright comets, were the key objects of interest. The brighter variable stars were monitored, but photography was in its infancy and digital imaging lay a century in the future. Today, at the start of the twenty-first century, amateurs are better equipped than any profess ...
... Moon and planets, as well as bright comets, were the key objects of interest. The brighter variable stars were monitored, but photography was in its infancy and digital imaging lay a century in the future. Today, at the start of the twenty-first century, amateurs are better equipped than any profess ...
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).