Cosmology and Particle Physics
... All observers see themselves as stationary; the other objects in space appear to be moving away from them. Hubble was directly responsible for discovering that the universe was much larger than had previously been imagined and that it had this amazing characteristic of rapid expansion. Universal exp ...
... All observers see themselves as stationary; the other objects in space appear to be moving away from them. Hubble was directly responsible for discovering that the universe was much larger than had previously been imagined and that it had this amazing characteristic of rapid expansion. Universal exp ...
THE PROPERTIES OF MAIN-SEQUENCE STARS - Cosmos
... The Hipparcos Catalogues give B , V for each programme star. Since these colours are from the literature rather than measured by Hipparcos, they will be subject to signi cant observational error (unlike our values of mV ). Nonetheless, it is interesting to study the colour distribution at xed spect ...
... The Hipparcos Catalogues give B , V for each programme star. Since these colours are from the literature rather than measured by Hipparcos, they will be subject to signi cant observational error (unlike our values of mV ). Nonetheless, it is interesting to study the colour distribution at xed spect ...
Spiral galaxies: Spiral galaxies: Inclination Spiral galaxies: Internal
... • In denser regions of the ISM, collisions between atoms become frequent enough to form molecules. • The most common molecule is H2, but since H2 is a symmetric molecule, it has no rotational quantum transitions. It is therefore extremely difficult to detect. • As a tracer of H2, astronomers usually ...
... • In denser regions of the ISM, collisions between atoms become frequent enough to form molecules. • The most common molecule is H2, but since H2 is a symmetric molecule, it has no rotational quantum transitions. It is therefore extremely difficult to detect. • As a tracer of H2, astronomers usually ...
Research News
... compared to the best bang-for-yourbuck explosions: supernovae. Granted, movie theatres are closer to home than violently dying stars, ...
... compared to the best bang-for-yourbuck explosions: supernovae. Granted, movie theatres are closer to home than violently dying stars, ...
Friday03
... large-scale densities (?) • Galaxy-galaxy interactions are the most likely cause of observed segregation ...
... large-scale densities (?) • Galaxy-galaxy interactions are the most likely cause of observed segregation ...
IR Spectroscopy
... passes beyond I band) Work well for z> 2.2, where the Lyman limit(912A) enters the U-band Connolly et al(1997) : including J band to solve the problem of determining z for 1
... passes beyond I band) Work well for z> 2.2, where the Lyman limit(912A) enters the U-band Connolly et al(1997) : including J band to solve the problem of determining z for 1
Interacting Galaxies
... While galaxies collide, with very rare exceptions, the stars within them do not. This is because so much of a galaxy is simply empty space, with distances between stars about 100 million times larger than their stellar diameters. What collides is the gas and dust between the stars, which produces a ...
... While galaxies collide, with very rare exceptions, the stars within them do not. This is because so much of a galaxy is simply empty space, with distances between stars about 100 million times larger than their stellar diameters. What collides is the gas and dust between the stars, which produces a ...
Galaxy Growth and Classification
... out once or twice. Now click on roughly 20 galaxies that you think are part of the cluster (make a note of what criteria you use to decide if these are cluster members). On the right hand side of this webpage, you will see the colors listed for the galaxy you clicked on, write these down. You can cl ...
... out once or twice. Now click on roughly 20 galaxies that you think are part of the cluster (make a note of what criteria you use to decide if these are cluster members). On the right hand side of this webpage, you will see the colors listed for the galaxy you clicked on, write these down. You can cl ...
Our Local Group of Galaxies
... The Sgr dSph has proved to be a very interesting object - has 4, perhaps 6+, globular clusters of its own, and is currently being disrupted by the tidal field of the Galaxy. Sgr stars are spread over a large part of the sky, tracing out the orbit. See Law & Majewski 2010 ApJ 714 229 and refs ...
... The Sgr dSph has proved to be a very interesting object - has 4, perhaps 6+, globular clusters of its own, and is currently being disrupted by the tidal field of the Galaxy. Sgr stars are spread over a large part of the sky, tracing out the orbit. See Law & Majewski 2010 ApJ 714 229 and refs ...
秋 夕(七言絕句) 作者:杜牧 銀燭秋光冷畫屏,輕羅小扇撲流螢。 天階夜色
... they are separated by only about 10 million miles, so from Spica's distance of 260 light-years, it is impossible to see them as individual stars. Because the stars are big, heavy, and close together, they exert such a strong gravitational tug on each other that each star causes the other to bulge ou ...
... they are separated by only about 10 million miles, so from Spica's distance of 260 light-years, it is impossible to see them as individual stars. Because the stars are big, heavy, and close together, they exert such a strong gravitational tug on each other that each star causes the other to bulge ou ...
TED Connection: Far, far away galaxies and why they matter
... 4. Lin argues that these galaxy clusters have four main uses, the first being to probe the very big. He shows an image of Abell 1689, a galaxy cluster with a trillion stars that is 2 million light years wide. The size of this cluster enables it to bend light and magnify the light of galaxies behind ...
... 4. Lin argues that these galaxy clusters have four main uses, the first being to probe the very big. He shows an image of Abell 1689, a galaxy cluster with a trillion stars that is 2 million light years wide. The size of this cluster enables it to bend light and magnify the light of galaxies behind ...
chapter15SurveyStars..
... It would be only 1/3 as bright It would be only 1/6 as bright It would be only 1/9 as bright It would be three times brighter ...
... It would be only 1/3 as bright It would be only 1/6 as bright It would be only 1/9 as bright It would be three times brighter ...
Distant Stars - How far away is it
... She found that the period of these stars varied in proportion to their absolute brightness. This was very interesting, because, as we have discussed, once we know the intrinsic luminosity of a star, we can easily calculate its distance. Leavitt‟s discovery made Cepheid stars true standard candles an ...
... She found that the period of these stars varied in proportion to their absolute brightness. This was very interesting, because, as we have discussed, once we know the intrinsic luminosity of a star, we can easily calculate its distance. Leavitt‟s discovery made Cepheid stars true standard candles an ...
How many galaxies are there in the Universe?
... 5. So how many stars are in the Universe ? Our Milky Way galaxy contains about 100 billion stars. It is slightly larger than average, so let us assume the average galaxy contains only 50 billion stars. Remember: 1 billion = 109 = 1,000,000,000 = 1 thousand million Estimate for total no. of stars in ...
... 5. So how many stars are in the Universe ? Our Milky Way galaxy contains about 100 billion stars. It is slightly larger than average, so let us assume the average galaxy contains only 50 billion stars. Remember: 1 billion = 109 = 1,000,000,000 = 1 thousand million Estimate for total no. of stars in ...
WFIRST-2.4: What Every Astronomer Should Know
... would be able to survey hundreds of nearby stars, enabling the characterization of dozens of known cool Jupiter-mass companions, the discovery and characterization of a similar number of cool Jupiter and Neptune companions, and the detection and characterization of debris disks in systems containin ...
... would be able to survey hundreds of nearby stars, enabling the characterization of dozens of known cool Jupiter-mass companions, the discovery and characterization of a similar number of cool Jupiter and Neptune companions, and the detection and characterization of debris disks in systems containin ...
Astronomy 730 / Galaxies
... zb. At t = t0 the boundary conditions are that σz(R, t0) = σz(0, t0) exp(−R/2hR) and hz(R, t0) = constant. If we take σz(R0,t0) = 20 km/s, we know that hz(R, t0) = 350 pc, again based on the old stars in the thin disk in the solar neighborhood. (c) Equate σz(R, t0) = σz(0, t0) exp(-R/2hR) with σz(R, ...
... zb. At t = t0 the boundary conditions are that σz(R, t0) = σz(0, t0) exp(−R/2hR) and hz(R, t0) = constant. If we take σz(R0,t0) = 20 km/s, we know that hz(R, t0) = 350 pc, again based on the old stars in the thin disk in the solar neighborhood. (c) Equate σz(R, t0) = σz(0, t0) exp(-R/2hR) with σz(R, ...
Astrophysical parameters of ten poorly studied open star clusters
... with the 2MASS J, H and Ks filters (Bonatto et al. 2004; Bica et al. 2006) to derive the cluster parameters. The simultaneous fittings were attempted on the J ∼ (J − H) and Ks ∼ (J − Ks ) diagrams for the inner stars, which should be less contaminated by the background field. If the number of stars ...
... with the 2MASS J, H and Ks filters (Bonatto et al. 2004; Bica et al. 2006) to derive the cluster parameters. The simultaneous fittings were attempted on the J ∼ (J − H) and Ks ∼ (J − Ks ) diagrams for the inner stars, which should be less contaminated by the background field. If the number of stars ...
Lecture 38. The Fermi Paradox, Von Neumann Machines
... vastly more expensive or dangerous than we think - maybe our desire to explore is unusual and other societies would not choose to leave their stars - maybe civilizations tend to destroy themselves 3. There is a galactic civilization and it is deliberately avoiding us / hiding their existence from us ...
... vastly more expensive or dangerous than we think - maybe our desire to explore is unusual and other societies would not choose to leave their stars - maybe civilizations tend to destroy themselves 3. There is a galactic civilization and it is deliberately avoiding us / hiding their existence from us ...
Life and Death of a Star The Universe Season 1 Episode 10
... years from now the Sun will reach this stage. Nuclear fusion will stop. The core has to be hotter to get Helium fusing. Harder to get Helium nuclei close together enough to fuse. 180 million will allow the Helium to fuse. Planetary Nebula: 100 million years burning Helium. The other layers of the ...
... years from now the Sun will reach this stage. Nuclear fusion will stop. The core has to be hotter to get Helium fusing. Harder to get Helium nuclei close together enough to fuse. 180 million will allow the Helium to fuse. Planetary Nebula: 100 million years burning Helium. The other layers of the ...
gravPart2
... • Turn the Sun’s velocity direction (keep amplitude) such that the Sun can fall into the BH at Galactic Centre. How accurate must the aiming be in term of angles in arcsec? Find input values from speed of the Sun, BH mass and distances from literature. • Consider a giant star (of 100solar radii, 1 s ...
... • Turn the Sun’s velocity direction (keep amplitude) such that the Sun can fall into the BH at Galactic Centre. How accurate must the aiming be in term of angles in arcsec? Find input values from speed of the Sun, BH mass and distances from literature. • Consider a giant star (of 100solar radii, 1 s ...
RASC Bulletin June 1996 - Royal Astronomical Society of Canada
... always a bad speller! The more important in sight was that one can do amazing things with ...
... always a bad speller! The more important in sight was that one can do amazing things with ...
Ivelina Sotirova Major: Biochemistry Senior at CUNY Hunter College
... ingenious idea of standard candles [3]. She showed that, by knowing the intrinsic luminosity properties of any distinguishable class of celestial bodies, one could measure distances of hundreds of thousands of light years away. But since Cepheids were only visible on the smaller cosmic scale, Walter ...
... ingenious idea of standard candles [3]. She showed that, by knowing the intrinsic luminosity properties of any distinguishable class of celestial bodies, one could measure distances of hundreds of thousands of light years away. But since Cepheids were only visible on the smaller cosmic scale, Walter ...
88K PDF file
... (a) What does this tell you about the relative temperatures of the two stars. (b) What does it tell you about their respective sizes? (a) The bluer star is hotter. (You don’t need to say anything about distance, relative size, luminosity, brightness, or anything else. If something is radiating therm ...
... (a) What does this tell you about the relative temperatures of the two stars. (b) What does it tell you about their respective sizes? (a) The bluer star is hotter. (You don’t need to say anything about distance, relative size, luminosity, brightness, or anything else. If something is radiating therm ...
Apparent Brightness, Parallax and the Distance to Sirius
... Apparent Brightness, Parallax and the Distance to Sirius ...
... Apparent Brightness, Parallax and the Distance to Sirius ...
Cosmic distance ladder
The cosmic distance ladder (also known as the extragalactic distance scale) is the succession of methods by which astronomers determine the distances to celestial objects. A real direct distance measurement of an astronomical object is possible only for those objects that are ""close enough"" (within about a thousand parsecs) to Earth. The techniques for determining distances to more distant objects are all based on various measured correlations between methods that work at close distances and methods that work at larger distances. Several methods rely on a standard candle, which is an astronomical object that has a known luminosity.The ladder analogy arises because no one technique can measure distances at all ranges encountered in astronomy. Instead, one method can be used to measure nearby distances, a second can be used to measure nearby to intermediate distances, and so on. Each rung of the ladder provides information that can be used to determine the distances at the next higher rung.