The Milky Way
... period “P” and separation “a” that obeys Kepler’s 3rd Law must have a total mass of 1 solar mass. ...
... period “P” and separation “a” that obeys Kepler’s 3rd Law must have a total mass of 1 solar mass. ...
Supplementary Information
... the limit of a thin and extended disk. The smearing due to the instrumental resolution in the spatial and spectral domains is taken into account by convolving the inclined model with the Gaussian point spread function of the appropriate width. The outputs of each model are full data cubes and veloci ...
... the limit of a thin and extended disk. The smearing due to the instrumental resolution in the spatial and spectral domains is taken into account by convolving the inclined model with the Gaussian point spread function of the appropriate width. The outputs of each model are full data cubes and veloci ...
Planisphere Exercise
... In what direction does the celestial equator appear to “rise” and “set” as the night progresses? Do these directions ever change? Turn the star wheel to find out. Look at the ecliptic, the path of the Sun among the background of stars over the course of a year. As the night progresses, does the ecli ...
... In what direction does the celestial equator appear to “rise” and “set” as the night progresses? Do these directions ever change? Turn the star wheel to find out. Look at the ecliptic, the path of the Sun among the background of stars over the course of a year. As the night progresses, does the ecli ...
Document
... • Point in any direction • That direction goes through empty space but ends on a star • Every direction should be as bright as the surface of a star • The sky should be bright at night • What’s wrong with this picture? ...
... • Point in any direction • That direction goes through empty space but ends on a star • Every direction should be as bright as the surface of a star • The sky should be bright at night • What’s wrong with this picture? ...
A105 Stars and Galaxies
... Close-in, massive planets are easier to detect Far-out planets and light-weight planets are MUCH HARDER to detect So far, we’ve only been able to detect massive, close-in planets Techniques, sensitivity are improving Terrestrial planets soon! ...
... Close-in, massive planets are easier to detect Far-out planets and light-weight planets are MUCH HARDER to detect So far, we’ve only been able to detect massive, close-in planets Techniques, sensitivity are improving Terrestrial planets soon! ...
Daynightseasonsstars-1
... 1. What is changing at the same (annual) timescale that we are observing the changing zodiac? 2. Do the constellations appear to change positions in the night sky as Earth travels around our Sun throughout the year? 3. Are the constellations themselves moving? 4. What causes this apparent change in ...
... 1. What is changing at the same (annual) timescale that we are observing the changing zodiac? 2. Do the constellations appear to change positions in the night sky as Earth travels around our Sun throughout the year? 3. Are the constellations themselves moving? 4. What causes this apparent change in ...
Chapter 1 The Copernican Revolution
... The dimensions of the Solar System Kepler’s Laws tell us the shape of the each planet’s orbital motion, the period and relative distance to the Sun (In AU ) but it doesn’t tell us about the actual size of the orbit (in kilometers). How many kilometers is one AU? How we can determine that? The moder ...
... The dimensions of the Solar System Kepler’s Laws tell us the shape of the each planet’s orbital motion, the period and relative distance to the Sun (In AU ) but it doesn’t tell us about the actual size of the orbit (in kilometers). How many kilometers is one AU? How we can determine that? The moder ...
November 2015 Eyepiece - Amateur Astronomers Association of
... Jupiter – The largest planet in our Solar System will be -1.4 magnitude amd up before dawn toward the east. This gas giant is named for the king of the gods in Roman mythology (Zeus to the Greeks). Mars – The Red Planet, does indeed appear red in our night sky. You can find Mars towards the east for ...
... Jupiter – The largest planet in our Solar System will be -1.4 magnitude amd up before dawn toward the east. This gas giant is named for the king of the gods in Roman mythology (Zeus to the Greeks). Mars – The Red Planet, does indeed appear red in our night sky. You can find Mars towards the east for ...
Astrophysics * Glossary - Uplift Summit International
... In 1960 it was proposed that sometime during the early history of the Universe it was at a sufficiently high temperature to produce helium by fusion. In this process many high energy photons would be produced. The CMB (Cosmic Microwave Background Radiation) radiation was emitted only a few hundred t ...
... In 1960 it was proposed that sometime during the early history of the Universe it was at a sufficiently high temperature to produce helium by fusion. In this process many high energy photons would be produced. The CMB (Cosmic Microwave Background Radiation) radiation was emitted only a few hundred t ...
year
... year may vary in the same calendar. For example, the Gregorian year contains 365 or 366 days (a leap year) and the Islamic year 354 or 355 days (a leap year). The Hebrew year has six possible year lengths (353, 354, 355, 383, 384 and 385 days). The latter three years are considered leap years due to ...
... year may vary in the same calendar. For example, the Gregorian year contains 365 or 366 days (a leap year) and the Islamic year 354 or 355 days (a leap year). The Hebrew year has six possible year lengths (353, 354, 355, 383, 384 and 385 days). The latter three years are considered leap years due to ...
Chapter10 (with interactive links)
... Measuring the color of a star tells us the surface temperature. The spectrum shifts to shorter wavelengths at higher temperatures. Wien’s law: “Hotter means bluer.” ...
... Measuring the color of a star tells us the surface temperature. The spectrum shifts to shorter wavelengths at higher temperatures. Wien’s law: “Hotter means bluer.” ...
PDF of story and photos
... MAGINE visiting a hospital to see thousands of babies being born at the same time. The weight of these newborns ranges from a few pounds to a ton (2,000 pounds). Does this story seem possible? The story may not be possible for babies, but it is an ordinary event for stars. In fact, the Hubble Space ...
... MAGINE visiting a hospital to see thousands of babies being born at the same time. The weight of these newborns ranges from a few pounds to a ton (2,000 pounds). Does this story seem possible? The story may not be possible for babies, but it is an ordinary event for stars. In fact, the Hubble Space ...
FREE Sample Here
... shows this method applied to astronomy using Earth’s diameter as a baseline. Challenge students to come up with a method where observers restricted to the surface of Earth can create an even longer baseline in order to measure parallaxes of more distant stars. (Observations can be made at different ...
... shows this method applied to astronomy using Earth’s diameter as a baseline. Challenge students to come up with a method where observers restricted to the surface of Earth can create an even longer baseline in order to measure parallaxes of more distant stars. (Observations can be made at different ...
Powerpoint slides
... Astronomers assume that most, if not all, spiral galaxies look pretty much the same. Therefore, this smaller-looking galaxy is probably a more distant galaxy. It is about five times as small as the larger-looking galaxy, so it is probably about five times farther…about two third of a mile away, on t ...
... Astronomers assume that most, if not all, spiral galaxies look pretty much the same. Therefore, this smaller-looking galaxy is probably a more distant galaxy. It is about five times as small as the larger-looking galaxy, so it is probably about five times farther…about two third of a mile away, on t ...
302 Final Review
... 64. A scientist looking for an optimal location for a new observatory should choose a location________. a. in a large city b. in an area with an elevation below sea level c. on a remote hilltop d. in a low-lying river valley ...
... 64. A scientist looking for an optimal location for a new observatory should choose a location________. a. in a large city b. in an area with an elevation below sea level c. on a remote hilltop d. in a low-lying river valley ...
Lecture 9: Stellar Spectra
... We can also determine the abundances of many elements in stars by using the “atomic fingerprints” seen in spectral absorption lines. We first determine (1) the star’s temperature (spectral class) (2) the star’s surface density (luminosity class) Once these are known, we can then estimate the abundan ...
... We can also determine the abundances of many elements in stars by using the “atomic fingerprints” seen in spectral absorption lines. We first determine (1) the star’s temperature (spectral class) (2) the star’s surface density (luminosity class) Once these are known, we can then estimate the abundan ...
Feb 2017 - Astronomical Society of Northern New England
... westward in the constellation of Virgo until it reverses direction once more in early June. That is just an illusion, since all of the planets are actually continuously orbiting counterclockwise around the sun all the time. They only appear to go retrograde at different times because we are in the s ...
... westward in the constellation of Virgo until it reverses direction once more in early June. That is just an illusion, since all of the planets are actually continuously orbiting counterclockwise around the sun all the time. They only appear to go retrograde at different times because we are in the s ...
Microsoft Power Point version
... The largest stars are in the upper right corner of the HR Diagram. Note that Absolute Magnitude is a measure of the Luminosity of the Star Apparent visual Magnitude is a measure of the Apparent Brightness (or Intensity) of the starlight reaching the observer. ...
... The largest stars are in the upper right corner of the HR Diagram. Note that Absolute Magnitude is a measure of the Luminosity of the Star Apparent visual Magnitude is a measure of the Apparent Brightness (or Intensity) of the starlight reaching the observer. ...
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).