Beers_First_Stars_NIC_School
... times the solar mass. No clear evidence of supernovae from such supermassive stars has, however, yet been found in the chemical compositions of Milky Way stars. Here we report on an analysis of a very metal-poor star, SDSS J001820.5−093939.2, which possesses elemental-abundance ratios that differ si ...
... times the solar mass. No clear evidence of supernovae from such supermassive stars has, however, yet been found in the chemical compositions of Milky Way stars. Here we report on an analysis of a very metal-poor star, SDSS J001820.5−093939.2, which possesses elemental-abundance ratios that differ si ...
pptx
... of old stars, seen in infra-red light which penetrates the dust slowly rotating, high in heavy elements (with wide spread) ...
... of old stars, seen in infra-red light which penetrates the dust slowly rotating, high in heavy elements (with wide spread) ...
The universe and our planet
... million. Towards the centre of the galaxy, the stars are close together, but in the outer areas of the galaxy they are farther apart. Stars are made up mainly of hydrogen and helium, the two most abundant gases in the universe. Many stars have planets that revolve around them forming planetary syste ...
... million. Towards the centre of the galaxy, the stars are close together, but in the outer areas of the galaxy they are farther apart. Stars are made up mainly of hydrogen and helium, the two most abundant gases in the universe. Many stars have planets that revolve around them forming planetary syste ...
1. Chapter 10
... days at a time. We have learned through experiments and observations that the stars are like our Sun, giving off light and heat, but are very far away. Thousands of years ago, what must people have thought when they looked up at the sky? Many people in early civilizations were farmers. They needed t ...
... days at a time. We have learned through experiments and observations that the stars are like our Sun, giving off light and heat, but are very far away. Thousands of years ago, what must people have thought when they looked up at the sky? Many people in early civilizations were farmers. They needed t ...
The Black Drop effect - ROSS
... seems to remain attached to the rim of the solar disc for a couple of seconds, becoming deformed and assuming a black drop shape. This phenomenon is repeated right before the last internal contact. This effect is known as the “Black-Drop” effect and it prevents the accurate measurements of the time ...
... seems to remain attached to the rim of the solar disc for a couple of seconds, becoming deformed and assuming a black drop shape. This phenomenon is repeated right before the last internal contact. This effect is known as the “Black-Drop” effect and it prevents the accurate measurements of the time ...
Astrophysics - Part 2
... Stefan’s law and Wien’s displacement law.General shape of black body curves, experimental verification is not required. Use of Wien’s displacement law to estimate black-body temperature of sources λmaxT = constant = 2.9 × 10-3 mK. Inverse square law, assumptions in its application. Use of Stefan’s l ...
... Stefan’s law and Wien’s displacement law.General shape of black body curves, experimental verification is not required. Use of Wien’s displacement law to estimate black-body temperature of sources λmaxT = constant = 2.9 × 10-3 mK. Inverse square law, assumptions in its application. Use of Stefan’s l ...
The Unified Theory of Stellar Evolution
... A black hole is a region of spacetime exhibiting such strong gravitational effects that nothing—not even particles and electromagnetic radiation such as light—can escape from inside it. The theory of gene ...
... A black hole is a region of spacetime exhibiting such strong gravitational effects that nothing—not even particles and electromagnetic radiation such as light—can escape from inside it. The theory of gene ...
The science case for - Astrophysics
... unexpected: indeed the majority of the science highlights of the first ten years of the first 10m telescope, the Keck, such as its part in the discovery and study of very high redshift, young ‘Lyman-break’ galaxies, were entirely new, violated received wisdom, and, being unknown, were not featured i ...
... unexpected: indeed the majority of the science highlights of the first ten years of the first 10m telescope, the Keck, such as its part in the discovery and study of very high redshift, young ‘Lyman-break’ galaxies, were entirely new, violated received wisdom, and, being unknown, were not featured i ...
Between the Stars: Gas and Dust in Space
... To understand how stars form, we need to know the raw material from which they are made All the gas and dust material that lies in the region between stars is referred to as interstellar matter The entire collection of interstellar matter is called the interstellar medium The interstellar medium acc ...
... To understand how stars form, we need to know the raw material from which they are made All the gas and dust material that lies in the region between stars is referred to as interstellar matter The entire collection of interstellar matter is called the interstellar medium The interstellar medium acc ...
talk.wyse - Johns Hopkins University
... Different baryonic histories, same dark matter halos (Gilmore et al, inc RW 07): not strong feedback from baryons to dark halo (cf Read et al 06, Fellhauer et al 08) ...
... Different baryonic histories, same dark matter halos (Gilmore et al, inc RW 07): not strong feedback from baryons to dark halo (cf Read et al 06, Fellhauer et al 08) ...
latest Edition - ExoPlanet News
... Kepler-78b is one of a growing sample of planets similar, in composition and size, to the Earth. It was first detected with NASA’s Kepler spacecraft and then characterised in more detail using radial velocity follow-up observations. Not only is its size very similar to that of the Earth (1.2R⊕ ), it ...
... Kepler-78b is one of a growing sample of planets similar, in composition and size, to the Earth. It was first detected with NASA’s Kepler spacecraft and then characterised in more detail using radial velocity follow-up observations. Not only is its size very similar to that of the Earth (1.2R⊕ ), it ...
Glossary of terms - Universal Workshop
... the rotation of the Earth. See Ast. Compan., POSITION. equinox: one of the 2 dates each year (about March 21 and September 23) when the Sun crosses the celestial equator. See Ast. Compan., SEASONS. Also, the 2 points on the map of the sky where this happens: the points where the ecliptic crosses the ...
... the rotation of the Earth. See Ast. Compan., POSITION. equinox: one of the 2 dates each year (about March 21 and September 23) when the Sun crosses the celestial equator. See Ast. Compan., SEASONS. Also, the 2 points on the map of the sky where this happens: the points where the ecliptic crosses the ...
Pictures in the Sky Teacher`s Guide
... Have your students color the planets on page 7 as described below. You may have to read the descriptions to your students, then see if they can figure out which planet is which and color it. The Sun: The Sun is not a planet but a star. It seems bigger, brighter, and hotter than the stars we see at n ...
... Have your students color the planets on page 7 as described below. You may have to read the descriptions to your students, then see if they can figure out which planet is which and color it. The Sun: The Sun is not a planet but a star. It seems bigger, brighter, and hotter than the stars we see at n ...
How Big is the Solar System?
... suddenly larger leap of 95 paces (more than twice as as the total distance walked up till then). This gap marks the boundary between the inner and outer solar systems. The inner solar system contains the four small, hard, "terrestrial" (Earth-like) planet; the outer solar system contains the four la ...
... suddenly larger leap of 95 paces (more than twice as as the total distance walked up till then). This gap marks the boundary between the inner and outer solar systems. The inner solar system contains the four small, hard, "terrestrial" (Earth-like) planet; the outer solar system contains the four la ...
Archaeoastronomy, Astronomy of Celts, A. Gaspani
... is one of the important means of establishing the cultural level reached by an ancient civilization. This is because stylistic motives, religious or philosophical doctrines may be developed independently by a culture and can travel great distances through a wide number of diffusion processes, while ...
... is one of the important means of establishing the cultural level reached by an ancient civilization. This is because stylistic motives, religious or philosophical doctrines may be developed independently by a culture and can travel great distances through a wide number of diffusion processes, while ...
Titan`s Methane Weather
... same wavelengths as the human eye, and they had seen Titan as only a fuzzy orange ball of photochemical haze. The 1990s brought the realization that Titan's surface and lower atmosphere might be observable at longer wavelengths (1-2 microns versus the approximately 0.5 micron wavelength of the human ...
... same wavelengths as the human eye, and they had seen Titan as only a fuzzy orange ball of photochemical haze. The 1990s brought the realization that Titan's surface and lower atmosphere might be observable at longer wavelengths (1-2 microns versus the approximately 0.5 micron wavelength of the human ...
matthewchristianstarprodject
... becomes cool to no longer give out significant heat or light. Since the required time for a white dwarf to reach the given state is calculated to be longer than the age of the universe of 13.7 billion years. No black dwarfs are expected to exist in the universe yet, but the temperature of the co ...
... becomes cool to no longer give out significant heat or light. Since the required time for a white dwarf to reach the given state is calculated to be longer than the age of the universe of 13.7 billion years. No black dwarfs are expected to exist in the universe yet, but the temperature of the co ...
Globular Clusters
... blue stars, fusing helium. They are considerably dimmer than the brightest red giants, but they can still be visible in photographs or with large telescopes. Blue Stragglers Dimmer yet, but still brighter than the sun-like yellow stars, are the "Blue Stragglers". These are large "main sequence" star ...
... blue stars, fusing helium. They are considerably dimmer than the brightest red giants, but they can still be visible in photographs or with large telescopes. Blue Stragglers Dimmer yet, but still brighter than the sun-like yellow stars, are the "Blue Stragglers". These are large "main sequence" star ...
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).