astronomy
... Discuss the nature of electromagnetic radiation, and tell how that radiation transfers energy and information through interstellar space. List the major regions of the electromagnetic spectrum and explain how the properties of the Earth’s atmosphere affect our ability to make astronomical observatio ...
... Discuss the nature of electromagnetic radiation, and tell how that radiation transfers energy and information through interstellar space. List the major regions of the electromagnetic spectrum and explain how the properties of the Earth’s atmosphere affect our ability to make astronomical observatio ...
mslien~1
... YSO & T Tauris still embedded circumstellar matter radiate in IR – distinguish b.m.o. IR excess in 2CD Need to investigate star formation in IR at first to characterize population Expand to multi-wavelength Radio complements IR: Mapping Some stars with IR excess have hotspots of ~ 7000K can get ...
... YSO & T Tauris still embedded circumstellar matter radiate in IR – distinguish b.m.o. IR excess in 2CD Need to investigate star formation in IR at first to characterize population Expand to multi-wavelength Radio complements IR: Mapping Some stars with IR excess have hotspots of ~ 7000K can get ...
1 AST 104 LAB 1 Temperature and Luminosity of Stars: Wein`s Law
... To understand how thermal spectra can be used to evaluate the temperature of a star To understand how temperature and radius of a star determine a star’s luminosity Introduction: In this activity we will learn how light from a star can tell us its temperature and how much energy per second the s ...
... To understand how thermal spectra can be used to evaluate the temperature of a star To understand how temperature and radius of a star determine a star’s luminosity Introduction: In this activity we will learn how light from a star can tell us its temperature and how much energy per second the s ...
Simple astronomy within the solar system
... (a) If the northern observer notes a zenith angle of = 7.2°, show that the radius of the earth is calculated to be 6.4 ∙ 108 cm. The two amateurs find that the second step necessary is to measure the velocity of the moon in its orbit about the center of the earth. They accomplish this indirectly b ...
... (a) If the northern observer notes a zenith angle of = 7.2°, show that the radius of the earth is calculated to be 6.4 ∙ 108 cm. The two amateurs find that the second step necessary is to measure the velocity of the moon in its orbit about the center of the earth. They accomplish this indirectly b ...
Astronomy Timeline
... 130 B.C. - Greek astronomer Hipparchus develops the first accurate star map and star catalogue, and a reliable method to predict solar eclipses 46 B.C. - Julius Caesar, after consulting the astronomer Sosigenes of Alexandria, introduces the Julian Calendar, a regular year of 365 days divided into 12 ...
... 130 B.C. - Greek astronomer Hipparchus develops the first accurate star map and star catalogue, and a reliable method to predict solar eclipses 46 B.C. - Julius Caesar, after consulting the astronomer Sosigenes of Alexandria, introduces the Julian Calendar, a regular year of 365 days divided into 12 ...
A stars
... However, massive, bright stars are much more short-lived than smaller, stars. In the case of the massive O stars and B main sequence stars, these very objects race through their life-cycles in only a few tens of millions of years – too quickly to allow even primitive life-forms to emerge. ...
... However, massive, bright stars are much more short-lived than smaller, stars. In the case of the massive O stars and B main sequence stars, these very objects race through their life-cycles in only a few tens of millions of years – too quickly to allow even primitive life-forms to emerge. ...
D1 Stellar quantities (PPT)
... ▪ Initially the cloud was about several light years across. A small overdensity in the cloud caused the contraction to begin and the overdensity to grow, thus producing a faster contraction ▪ Initially, most of the motions of the cloud particles were random, yet the nebula had a net rotation. As col ...
... ▪ Initially the cloud was about several light years across. A small overdensity in the cloud caused the contraction to begin and the overdensity to grow, thus producing a faster contraction ▪ Initially, most of the motions of the cloud particles were random, yet the nebula had a net rotation. As col ...
April - Bristol Astronomical Society
... The southern part of the sky is dominated by the constellation of Leo, one of the few constellations that resembles the object it is supposed to represent, in the case of Leo, a Lion. One of the many myths connected to Leo is that it represents the Nemean Lion which was killed by Hercules as the fir ...
... The southern part of the sky is dominated by the constellation of Leo, one of the few constellations that resembles the object it is supposed to represent, in the case of Leo, a Lion. One of the many myths connected to Leo is that it represents the Nemean Lion which was killed by Hercules as the fir ...
HR Diagram - Geneva 304
... 50. Where and when can the Pleiades be found? 51. Compare and contrast stellar Population I with stellar Population II. Do the stars in the galactic cluster Pleiades belong to stellar Population I or II? ...
... 50. Where and when can the Pleiades be found? 51. Compare and contrast stellar Population I with stellar Population II. Do the stars in the galactic cluster Pleiades belong to stellar Population I or II? ...
JMB CREIL 2
... 1. 3. The Coherent Raman effect on incoherent light. Several beams induce several polarisation states which interact. As the polarisation state have the same parity, the interaction must be of Raman type, for instance quadrupolar electric. To agree with thermodynamics, the beams which have the high ...
... 1. 3. The Coherent Raman effect on incoherent light. Several beams induce several polarisation states which interact. As the polarisation state have the same parity, the interaction must be of Raman type, for instance quadrupolar electric. To agree with thermodynamics, the beams which have the high ...
Teacher notes and student sheets
... There are a lot of stars in the galaxy – about 100 billion, which we can write as 100 000 000 000 or as 1011. That is the value of S in the equation. Since the 1990s, very many ‘exoplanets’ have been found. It is estimated that much more than 10% of Sun-like stars have planets in orbit around them. ...
... There are a lot of stars in the galaxy – about 100 billion, which we can write as 100 000 000 000 or as 1011. That is the value of S in the equation. Since the 1990s, very many ‘exoplanets’ have been found. It is estimated that much more than 10% of Sun-like stars have planets in orbit around them. ...
Celestial Motions - Stony Brook Astronomy
... • What does the universe look like from Earth? • Why do stars rise and set? • How does the sky change with latitude and over the year? ...
... • What does the universe look like from Earth? • Why do stars rise and set? • How does the sky change with latitude and over the year? ...
Wednesday, November 7, 2007
... • This shrunken remnant is a white dwarf. It slowly loses energy to space and cools but otherwise doesn’t change. The cloud of ejected matter around a newly formed white dwarf is called a planetary nebula. because ...
... • This shrunken remnant is a white dwarf. It slowly loses energy to space and cools but otherwise doesn’t change. The cloud of ejected matter around a newly formed white dwarf is called a planetary nebula. because ...
The H-R Diagram
... • Parallax, the only direct method of finding distances to stars, except for rare eclipsing binaries • Spectral types are a Temperature sequence: OBAFGKM hot to cool. • 90% of all stars are on Main Sequence= hydrogen burning stars • Main Sequence is a mass sequence, lower right to upper left is risi ...
... • Parallax, the only direct method of finding distances to stars, except for rare eclipsing binaries • Spectral types are a Temperature sequence: OBAFGKM hot to cool. • 90% of all stars are on Main Sequence= hydrogen burning stars • Main Sequence is a mass sequence, lower right to upper left is risi ...
test - Scioly.org
... 14. What type of star is shown on the right side of this illustration? 15. What is the name of the material spiraling around and into the left hand star? 16. Expressed in solar masses, a type 1a supernova will occur when the left hand star reaches what mass? 17. Expressed in kg, and in scientific no ...
... 14. What type of star is shown on the right side of this illustration? 15. What is the name of the material spiraling around and into the left hand star? 16. Expressed in solar masses, a type 1a supernova will occur when the left hand star reaches what mass? 17. Expressed in kg, and in scientific no ...
printer-friendly sample test questions
... to other stars. Depth of Knowledge Level 1 1. When observed from Earth on a clear night, the Milky Way Galaxy appears as a A. circular pattern of stars. B. elliptical pattern of stars. C. glowing band of light. D. random spotting of light. 2. How many times greater is Sun’s diameter than Earth’s dia ...
... to other stars. Depth of Knowledge Level 1 1. When observed from Earth on a clear night, the Milky Way Galaxy appears as a A. circular pattern of stars. B. elliptical pattern of stars. C. glowing band of light. D. random spotting of light. 2. How many times greater is Sun’s diameter than Earth’s dia ...
Stefan-Boltzmann`s law Wien`s law
... Binary star is a stellar system consisting of two stars orbiting around their common center of mass. The ONLY way to find mass of the stars is when they are the part of binary stars. Knowing the period of the binary and the separation of the stars the total mass of the binary system can be calculate ...
... Binary star is a stellar system consisting of two stars orbiting around their common center of mass. The ONLY way to find mass of the stars is when they are the part of binary stars. Knowing the period of the binary and the separation of the stars the total mass of the binary system can be calculate ...
Week 20 Satellites and Probes
... HST even though it will be observing primarily in infrared (whereas HST observed in both infrared and visible [primarily visible]). The JWST was nearly canceled by Congress and NASA multiple times over its development due to managerial snafus causing extreme budget overruns, but it is now fairly wel ...
... HST even though it will be observing primarily in infrared (whereas HST observed in both infrared and visible [primarily visible]). The JWST was nearly canceled by Congress and NASA multiple times over its development due to managerial snafus causing extreme budget overruns, but it is now fairly wel ...
1 light year = 9 x 10 12 km
... • Light is the fastest thing in the universe, but even light travels at a finite speed. • Speed of light = 186,000 miles 60 seconds 60 minutes ...
... • Light is the fastest thing in the universe, but even light travels at a finite speed. • Speed of light = 186,000 miles 60 seconds 60 minutes ...
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).