It`s a bird, it`s a plane…
... • They form tails when they pass through the inner solar system • They orbit the sun in large ellipses, and can go in the same or different directions as the planets. • They usually remain in the outermost regions of the solar system. ...
... • They form tails when they pass through the inner solar system • They orbit the sun in large ellipses, and can go in the same or different directions as the planets. • They usually remain in the outermost regions of the solar system. ...
Lecture 13: The stars are suns
... parallax of stars that are less than 300 ly (92 pc) away. Distances to 10,000 stars have been measured this way. 1989-1993: Hipparcos satellite measured parallax for 120,000 stars, maximum distance: a few x 103 pc. In 2011: Gaia will measure parallax for 1 billion stars. • Back to Stellar Luminosity ...
... parallax of stars that are less than 300 ly (92 pc) away. Distances to 10,000 stars have been measured this way. 1989-1993: Hipparcos satellite measured parallax for 120,000 stars, maximum distance: a few x 103 pc. In 2011: Gaia will measure parallax for 1 billion stars. • Back to Stellar Luminosity ...
Inquiry Lab: Exploring the Spectrum Intended Learning Outcomes: 1
... 3. What can be inferred from the spectral analysis of distant galaxies? (Guided Inquiry – Parts C and D) Background for Teachers: Students need to understand the Doppler Effect. This was covered in the previous lesson plan. Through experimentation, observation, and effective teacher questioning, stu ...
... 3. What can be inferred from the spectral analysis of distant galaxies? (Guided Inquiry – Parts C and D) Background for Teachers: Students need to understand the Doppler Effect. This was covered in the previous lesson plan. Through experimentation, observation, and effective teacher questioning, stu ...
the universe
... Scientists have gathered a lot of evidence and information about the universe. They have used their observations to develop a theory called the Big Bang. The theory states that about 13,700 million years ago all the matter in the universe was concentrated into a single incredibly tiny point. This be ...
... Scientists have gathered a lot of evidence and information about the universe. They have used their observations to develop a theory called the Big Bang. The theory states that about 13,700 million years ago all the matter in the universe was concentrated into a single incredibly tiny point. This be ...
the universe
... Scientists have gathered a lot of evidence and information about the universe. They have used their observations to develop a theory called the Big Bang. The theory states that about 13,700 million years ago all the matter in the universe was concentrated into a single incredibly tiny point. This be ...
... Scientists have gathered a lot of evidence and information about the universe. They have used their observations to develop a theory called the Big Bang. The theory states that about 13,700 million years ago all the matter in the universe was concentrated into a single incredibly tiny point. This be ...
Chapter 07
... If a star is moving toward Earth, the lines in its spectrum are shifted slightly toward shorter wavelength (higher frequency). This shifts the absorption lines toward the blue end of the spectrum, so it’s called a blue shift. If a star is moving away from Earth, the lines in its spectrum are shifted ...
... If a star is moving toward Earth, the lines in its spectrum are shifted slightly toward shorter wavelength (higher frequency). This shifts the absorption lines toward the blue end of the spectrum, so it’s called a blue shift. If a star is moving away from Earth, the lines in its spectrum are shifted ...
Earth
... •Example: a star of 0.7 solar masses would produce a neutron star with a radius of just 10 km. •Even if this object had a surface temperature of 50,000 K, it would have such a small radius that its total luminosity would be a million times fainter than the Sun. ...
... •Example: a star of 0.7 solar masses would produce a neutron star with a radius of just 10 km. •Even if this object had a surface temperature of 50,000 K, it would have such a small radius that its total luminosity would be a million times fainter than the Sun. ...
previous mid-term () - Department of Physics and Astronomy
... 56. The planets formed into two main groups: the inner terrestrial planets and the outer Jovian planets. Which of the following is NOT characteristic of the formation sequence of the terrestrial planets? a. Heavy elements condense to form grains and then planetesimals. b. Planetesimals coalesce and ...
... 56. The planets formed into two main groups: the inner terrestrial planets and the outer Jovian planets. Which of the following is NOT characteristic of the formation sequence of the terrestrial planets? a. Heavy elements condense to form grains and then planetesimals. b. Planetesimals coalesce and ...
3A8d
... (d) Estimate the bolometric luminosity of the protogalaxy, averaged over the free-fall time. For this calculation you may assume that the stars of relevance convert 10% of their mass into energy with an efficiency 0.01 mc2 (this includes a contribution from supernovae). Assume a Salpeter IMF and the ...
... (d) Estimate the bolometric luminosity of the protogalaxy, averaged over the free-fall time. For this calculation you may assume that the stars of relevance convert 10% of their mass into energy with an efficiency 0.01 mc2 (this includes a contribution from supernovae). Assume a Salpeter IMF and the ...
EXAM II REVIEW - University of Maryland: Department of
... Motion toward or away from an observer causes a shift in the observed wavelength of light: • blueshift (shorter wavelength) motion toward you ...
... Motion toward or away from an observer causes a shift in the observed wavelength of light: • blueshift (shorter wavelength) motion toward you ...
Linking Asteroids and Meteorites through Reflectance
... • If Earth orbited the Sun, ancient astronomers believed that they would see differences in angular separation of stars as the Earth rotated around the Sun • Since they saw no changes in angular separation of the stars, they assumed the Earth was the center of the universe • They could not fathom th ...
... • If Earth orbited the Sun, ancient astronomers believed that they would see differences in angular separation of stars as the Earth rotated around the Sun • Since they saw no changes in angular separation of the stars, they assumed the Earth was the center of the universe • They could not fathom th ...
ASTR0 100 HW #4 – SOLUTIONS – 2 points each
... ASTR0 100 HW #4 – SOLUTIONS – 2 points each Chapter 5 24. Thanks to adaptive optics, the telescope on Mount Wilson can now make ultraviolet images of the cosmos. False. While Mount Wilson does have adaptive optics, it is a ground based telescope, and so it cannot do observing in ultraviolet because ...
... ASTR0 100 HW #4 – SOLUTIONS – 2 points each Chapter 5 24. Thanks to adaptive optics, the telescope on Mount Wilson can now make ultraviolet images of the cosmos. False. While Mount Wilson does have adaptive optics, it is a ground based telescope, and so it cannot do observing in ultraviolet because ...
U7 Review WS KEY
... b. cosmic background radiation d. abundance of light elements (H, He and Li) The first elements that were formed in the universe were? a. hydrogen and lithium c. hydrogen and helium b. lithium and helium d. lithium and beryllium 10. I can describe tools and models used by scientists to predict the ...
... b. cosmic background radiation d. abundance of light elements (H, He and Li) The first elements that were formed in the universe were? a. hydrogen and lithium c. hydrogen and helium b. lithium and helium d. lithium and beryllium 10. I can describe tools and models used by scientists to predict the ...
The Universe and Galaxies - West Jefferson Local Schools
... - Dark energy – theoretical energy that might be causing accelerated expansion of the universe ...
... - Dark energy – theoretical energy that might be causing accelerated expansion of the universe ...
The Evening Sky in February 2016
... Rigel and reddish Betelgeuse. Between them is the line of three stars making Orion's Belt. The Belt line points left and down to orange Aldebaran, the eye of Taurus the Bull. Continuing the same line finds a tight bunch of fainter stars making the Pleiades/Matariki star cluster. In the late evening, ...
... Rigel and reddish Betelgeuse. Between them is the line of three stars making Orion's Belt. The Belt line points left and down to orange Aldebaran, the eye of Taurus the Bull. Continuing the same line finds a tight bunch of fainter stars making the Pleiades/Matariki star cluster. In the late evening, ...
The Milky Way Galaxy
... Shapley’s model Globular clusters must orbit around the center of mass of the galaxy! Thus, assuming the clusters are distributed uniformly around the galaxy, he measured the 3D distribution of clusters (using Cepheid variables) and then assumed that the center of that distribution was where the cen ...
... Shapley’s model Globular clusters must orbit around the center of mass of the galaxy! Thus, assuming the clusters are distributed uniformly around the galaxy, he measured the 3D distribution of clusters (using Cepheid variables) and then assumed that the center of that distribution was where the cen ...
Stars
... The brightness of a star depends on size and temperature How bright a star looks depends on distance from Earth and actual brightness Apparent magnitude: brightness as seen from Earth Absolute magnitude: brightness if it were a standard distance from Earth ...
... The brightness of a star depends on size and temperature How bright a star looks depends on distance from Earth and actual brightness Apparent magnitude: brightness as seen from Earth Absolute magnitude: brightness if it were a standard distance from Earth ...
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).