![Measuring Our Universe](http://s1.studyres.com/store/data/008814834_1-43f980e980a1abf116744047392075d7-300x300.png)
Measuring Our Universe
... value of AU, Cassini unlocked the distances and sizes of other planets in the solar system. This gave us, for the first time in the history of our species, an accurate understanding of the scale of our Solar System. For example, using the modern value for the average angular diameter of the Sun of 0 ...
... value of AU, Cassini unlocked the distances and sizes of other planets in the solar system. This gave us, for the first time in the history of our species, an accurate understanding of the scale of our Solar System. For example, using the modern value for the average angular diameter of the Sun of 0 ...
Determining Distances to Other Galaxies
... If stars in the disk of a spiral galaxy are on slightly eccentric orbits, and the position angle of these ellipses vary with radius, a spiral-shaped density wave can be formed from a set of nested ovals. Density wave theory is really based on the premise that mutual gravitational attraction of stars ...
... If stars in the disk of a spiral galaxy are on slightly eccentric orbits, and the position angle of these ellipses vary with radius, a spiral-shaped density wave can be formed from a set of nested ovals. Density wave theory is really based on the premise that mutual gravitational attraction of stars ...
SUMSS - 京都大学
... • Singularities are points of infinite gravity, or more accurately, infinite spacetime curvature, where space and time end. ...
... • Singularities are points of infinite gravity, or more accurately, infinite spacetime curvature, where space and time end. ...
Stars and Galaxies
... shifted towards the red part of the visible spectrum The faster they move away from us, the more they are redshifted. Thus, redshift is a reasonable way to measure the speed of an object. When we observe the redshift of galaxies, almost every galaxy appears to be moving away from us – the Univer ...
... shifted towards the red part of the visible spectrum The faster they move away from us, the more they are redshifted. Thus, redshift is a reasonable way to measure the speed of an object. When we observe the redshift of galaxies, almost every galaxy appears to be moving away from us – the Univer ...
Stars and Galaxies
... shifted towards the red part of the visible spectrum The faster they move away from us, the more they are redshifted. Thus, redshift is a reasonable way to measure the speed of an object. When we observe the redshift of galaxies, almost every galaxy appears to be moving away from us – the Univer ...
... shifted towards the red part of the visible spectrum The faster they move away from us, the more they are redshifted. Thus, redshift is a reasonable way to measure the speed of an object. When we observe the redshift of galaxies, almost every galaxy appears to be moving away from us – the Univer ...
Lecture 12: Galaxies View of the Galaxy from within Comparison to
... By plotting the distances of globular clusters (estimated using regular variable stars) we can determine the sun’s location relative to the stellar halo of the Galaxy. We conclude that our Sun lies within the galactic disk, some 8000 pc (26,000 ly) from the Galactic centre. ...
... By plotting the distances of globular clusters (estimated using regular variable stars) we can determine the sun’s location relative to the stellar halo of the Galaxy. We conclude that our Sun lies within the galactic disk, some 8000 pc (26,000 ly) from the Galactic centre. ...
Exploring Space—The Universe: The Vast
... 5. Discuss the Big Bang theory with the class. According to scientists, when did the “Big Bang” occur? (12 to 13 billion years ago.) How has the Hubble telescope been able to prove this theory? Explain how the Hubble telescope has been able to detect that galaxies are gradually moving away from each ...
... 5. Discuss the Big Bang theory with the class. According to scientists, when did the “Big Bang” occur? (12 to 13 billion years ago.) How has the Hubble telescope been able to prove this theory? Explain how the Hubble telescope has been able to detect that galaxies are gradually moving away from each ...
Cosmological Aspects of Nucleosynthesis
... (2) As consequence of the compactness of the star , it cannot evolve to become red giants. They remain confined to the blue part of the HR diagram, when Z<10-3 . As seen on next page, the hydrogen-burning shell remains convective all the time. More details are found in : ...
... (2) As consequence of the compactness of the star , it cannot evolve to become red giants. They remain confined to the blue part of the HR diagram, when Z<10-3 . As seen on next page, the hydrogen-burning shell remains convective all the time. More details are found in : ...
Dynamics of elliptical galaxies
... from the center of the galaxy to the edge. This can be interpreted as a projection effect of a triaxial galaxy in which the ellipticity changes with radius: ...
... from the center of the galaxy to the edge. This can be interpreted as a projection effect of a triaxial galaxy in which the ellipticity changes with radius: ...
Galaxies
... The Universe is filled with these star systems which themselves cluster together into larger systems. ...
... The Universe is filled with these star systems which themselves cluster together into larger systems. ...
Document
... The Universe is filled with these star systems which themselves cluster together into larger systems. ...
... The Universe is filled with these star systems which themselves cluster together into larger systems. ...
chapter 26 instructor notes
... low-metallicity stars from the Galaxy’s formation has not had time to evolve away from the main sequence. Perhaps the amount of matter in stars in the Galactic disk has increased significantly since the formation of the Galaxy? Or perhaps very few low-mass stars were formed early in the Galaxy’s his ...
... low-metallicity stars from the Galaxy’s formation has not had time to evolve away from the main sequence. Perhaps the amount of matter in stars in the Galactic disk has increased significantly since the formation of the Galaxy? Or perhaps very few low-mass stars were formed early in the Galaxy’s his ...
Word
... significantly in order to get a more realistic animation, which is closer to the real case of the galaxy. 2.Since we can calculate the velocities, accelerations and positions of the particles by cutting the time to many very small intervals only, the time step must be as small as possible in order t ...
... significantly in order to get a more realistic animation, which is closer to the real case of the galaxy. 2.Since we can calculate the velocities, accelerations and positions of the particles by cutting the time to many very small intervals only, the time step must be as small as possible in order t ...
Galaxies
... significantly in order to get a more realistic animation, which is closer to the real case of the galaxy. 2.Since we can calculate the velocities, accelerations and positions of the particles by cutting the time to many very small intervals only, the time step must be as small as possible in order t ...
... significantly in order to get a more realistic animation, which is closer to the real case of the galaxy. 2.Since we can calculate the velocities, accelerations and positions of the particles by cutting the time to many very small intervals only, the time step must be as small as possible in order t ...
Science Says: What Scientific Evidence Can Say About the
... together to form heavy elements and too few would remain as the lighter elements such as hydrogen and helium, both of which are fuel for stars. Without these two elements, stable, long-living stars would never form and life anywhere in the universe would certainly never exist. If the universe expan ...
... together to form heavy elements and too few would remain as the lighter elements such as hydrogen and helium, both of which are fuel for stars. Without these two elements, stable, long-living stars would never form and life anywhere in the universe would certainly never exist. If the universe expan ...
TAP 704- 8: The ladder of astronomical distances
... The prestigious meeting of the International Astronomical Union in 1976 was startled to be told that the Universe is only half as big as the astronomers present all thought, and therefore only half as old. The challenger was the French-American astronomer Gerard de Vaucouleurs; the leader of the cha ...
... The prestigious meeting of the International Astronomical Union in 1976 was startled to be told that the Universe is only half as big as the astronomers present all thought, and therefore only half as old. The challenger was the French-American astronomer Gerard de Vaucouleurs; the leader of the cha ...
Contents - Classroom Complete Press
... a) Label the diagrams using the following words: star, solar system, galaxy. ...
... a) Label the diagrams using the following words: star, solar system, galaxy. ...
Test #4
... c) They vary on rapid time scales. d) They can be seen clearly; we can see that the energy source is compact. 8. Why are quasars called “quasi-stellar”? a) Their spectra strongly resemble the spectra of stars. b) They are ordinary stars located at vast distances from Earth. c) They look like stars o ...
... c) They vary on rapid time scales. d) They can be seen clearly; we can see that the energy source is compact. 8. Why are quasars called “quasi-stellar”? a) Their spectra strongly resemble the spectra of stars. b) They are ordinary stars located at vast distances from Earth. c) They look like stars o ...
Astronomy - Career Account Web Pages
... The most distant objects in the universe appear extremely red because their light is stretched to longer, redder wavelengths by the expansion of the universe. This object is at an extremely faint magnitude of 29, which is 500 million times fainter that the faintest stars seen by the human eye. The d ...
... The most distant objects in the universe appear extremely red because their light is stretched to longer, redder wavelengths by the expansion of the universe. This object is at an extremely faint magnitude of 29, which is 500 million times fainter that the faintest stars seen by the human eye. The d ...
observing the universe
... center. A black hole is an extremely dense body of matter, formed by the collapse of a massive star’s core, with a gravitational pull so strong nothing can escape. The study of this celestial phenomenon is somewhat tough. A black hole can’t actually be seen because the gravitational pull is so stron ...
... center. A black hole is an extremely dense body of matter, formed by the collapse of a massive star’s core, with a gravitational pull so strong nothing can escape. The study of this celestial phenomenon is somewhat tough. A black hole can’t actually be seen because the gravitational pull is so stron ...
Astro 6590: Galaxies and the Universe Astro
... Not only do redshifts help the identification of group or cluster members, they also prove useful to indicate masses, identify substructure and detail evolutionary processes at work e.g. use Virial Theorem to estimate mass of cluster of galaxies ...
... Not only do redshifts help the identification of group or cluster members, they also prove useful to indicate masses, identify substructure and detail evolutionary processes at work e.g. use Virial Theorem to estimate mass of cluster of galaxies ...
Assignment 10
... ____ 12. Which of the following statements about the implications of Hubble's Law is FALSE? a. the law implies that the whole universe must be expanding b. the law can be used to measure distances to remote galaxies for which we can measure a Doppler shift c. the law does NOT require us to be at th ...
... ____ 12. Which of the following statements about the implications of Hubble's Law is FALSE? a. the law implies that the whole universe must be expanding b. the law can be used to measure distances to remote galaxies for which we can measure a Doppler shift c. the law does NOT require us to be at th ...
AST 207 Test 3 23 November 2009
... a. (1 pt.) At the present time, does the value of Hubble’s constant depend on the galaxy in which the observations are made? (2 pts.) Explain your reasoning. b. Simplicio erroneously believes that everything in the universe is expanding according to Hubble’s Law. At an earlier time, everything did o ...
... a. (1 pt.) At the present time, does the value of Hubble’s constant depend on the galaxy in which the observations are made? (2 pts.) Explain your reasoning. b. Simplicio erroneously believes that everything in the universe is expanding according to Hubble’s Law. At an earlier time, everything did o ...
Classification and structure of galaxies
... half a million miles per hour around the center of the Galaxy • takes our Solar System about 200 million years to revolve once around our galaxy ...
... half a million miles per hour around the center of the Galaxy • takes our Solar System about 200 million years to revolve once around our galaxy ...
Observable universe
![](https://commons.wikimedia.org/wiki/Special:FilePath/Observable_Universe_with_Measurements_01.png?width=300)
The observable universe consists of the galaxies and other matter that can, in principle, be observed from Earth at the present time because light and other signals from these objects has had time to reach the Earth since the beginning of the cosmological expansion. Assuming the universe is isotropic, the distance to the edge of the observable universe is roughly the same in every direction. That is, the observable universe is a spherical volume (a ball) centered on the observer. Every location in the Universe has its own observable universe, which may or may not overlap with the one centered on Earth.The word observable used in this sense does not depend on whether modern technology actually permits detection of radiation from an object in this region (or indeed on whether there is any radiation to detect). It simply indicates that it is possible in principle for light or other signals from the object to reach an observer on Earth. In practice, we can see light only from as far back as the time of photon decoupling in the recombination epoch. That is when particles were first able to emit photons that were not quickly re-absorbed by other particles. Before then, the Universe was filled with a plasma that was opaque to photons.The surface of last scattering is the collection of points in space at the exact distance that photons from the time of photon decoupling just reach us today. These are the photons we detect today as cosmic microwave background radiation (CMBR). However, with future technology, it may be possible to observe the still older relic neutrino background, or even more distant events via gravitational waves (which also should move at the speed of light). Sometimes astrophysicists distinguish between the visible universe, which includes only signals emitted since recombination—and the observable universe, which includes signals since the beginning of the cosmological expansion (the Big Bang in traditional cosmology, the end of the inflationary epoch in modern cosmology). According to calculations, the comoving distance (current proper distance) to particles from the CMBR, which represent the radius of the visible universe, is about 14.0 billion parsecs (about 45.7 billion light years), while the comoving distance to the edge of the observable universe is about 14.3 billion parsecs (about 46.6 billion light years), about 2% larger.The best estimate of the age of the universe as of 2015 is 7010137990000000000♠13.799±0.021 billion years but due to the expansion of space humans are observing objects that were originally much closer but are now considerably farther away (as defined in terms of cosmological proper distance, which is equal to the comoving distance at the present time) than a static 13.8 billion light-years distance. It is estimated that the diameter of the observable universe is about 28 gigaparsecs (91 billion light-years, 8.8×1026 metres or 5.5×1023 miles), putting the edge of the observable universe at about 46–47 billion light-years away.