Chapter 3 Cosmology 3.1 The Doppler effect
... by the unaided eye on a clear night. By taking photographs of Andromeda using a large telescope, Edwin Hubble was able to identify Cepheid variable stars in Andromeda. These stars vary in brightness with a period of the order of days and are named after the first one to be discovered, -Cephei, the ...
... by the unaided eye on a clear night. By taking photographs of Andromeda using a large telescope, Edwin Hubble was able to identify Cepheid variable stars in Andromeda. These stars vary in brightness with a period of the order of days and are named after the first one to be discovered, -Cephei, the ...
Journey to the Stars Educator`s Guide
... nuclear fusion occurs, producing energy. The outward pressure of gas heated by fusion is balanced by the inward pull of gravity, leaving the star in hydrostatic equilibrium. This balance of forces lasts for most of a star’s life, maintaining its steady temperature. Radiation and convection carry the ...
... nuclear fusion occurs, producing energy. The outward pressure of gas heated by fusion is balanced by the inward pull of gravity, leaving the star in hydrostatic equilibrium. This balance of forces lasts for most of a star’s life, maintaining its steady temperature. Radiation and convection carry the ...
question - UW Canvas
... 13. What else can be inferred from the graph for each of the CMDs shown in Figure 4? a. The locations or coordinates on the celestial sphere where the clusters are located. b. How fast each cluster is moving relative to Earth; i.e., spectral redshifts or blueshifts. c. The value of Hubble’s constant ...
... 13. What else can be inferred from the graph for each of the CMDs shown in Figure 4? a. The locations or coordinates on the celestial sphere where the clusters are located. b. How fast each cluster is moving relative to Earth; i.e., spectral redshifts or blueshifts. c. The value of Hubble’s constant ...
Pop Quiz Question
... while the star Kayak has a parallax of 50 mas. They are the same brightness. This means that: A. Kayak is twice as luminous as Racecar B. Racecar is twice as luminous as Kayak C. Racecar is four times as luminous as Kayak D. Kayak is four times as luminous as Racecar ...
... while the star Kayak has a parallax of 50 mas. They are the same brightness. This means that: A. Kayak is twice as luminous as Racecar B. Racecar is twice as luminous as Kayak C. Racecar is four times as luminous as Kayak D. Kayak is four times as luminous as Racecar ...
PDF file - Memorie della SAIt
... companion. Then, the C and s-element enhancements are ashes of the nucleosynthesis occurred in the He-rich inter-shell of a low metallicity AGB star. We present a calculation of a Z=5 × 10−5 low mass (M=1.5 M ) AGB stellar model. A full network including all the relevant isotopes up to the end poin ...
... companion. Then, the C and s-element enhancements are ashes of the nucleosynthesis occurred in the He-rich inter-shell of a low metallicity AGB star. We present a calculation of a Z=5 × 10−5 low mass (M=1.5 M ) AGB stellar model. A full network including all the relevant isotopes up to the end poin ...
Chapter 14 Neutron Stars and Black holes
... 16. Which of the following describes the gravitational red shift? a. The reddening of starlight by interstellar dust grains. b. A reduction in the energy of photons as they move away from objects. c. The angular change in a star's position when observed during a solar eclipse. d. The alternating Dop ...
... 16. Which of the following describes the gravitational red shift? a. The reddening of starlight by interstellar dust grains. b. A reduction in the energy of photons as they move away from objects. c. The angular change in a star's position when observed during a solar eclipse. d. The alternating Dop ...
Feedback - Cambridge University Press
... i.e., only 22% of the baryons associated with the dark matter halo make their way into stars. Inventories of both stars and gas suggest that the most massive clusters contain most if not all of their cosmic abundance of baryons, i.e., fb ≈ fb,cos (Leauthaud et al. 2012, Dai et al. 2010). Lower mass ...
... i.e., only 22% of the baryons associated with the dark matter halo make their way into stars. Inventories of both stars and gas suggest that the most massive clusters contain most if not all of their cosmic abundance of baryons, i.e., fb ≈ fb,cos (Leauthaud et al. 2012, Dai et al. 2010). Lower mass ...
LESSON 8: STARS
... stars range in colour from red through yellow and white to blue. The Sun’s yellow surface is about 5800K (Kelvin), while some red stars are 3000K and blue stars can have surface temperatures of over 30 000K. When we look up at the stars, they all appear to dazzle bright white, but many stars actuall ...
... stars range in colour from red through yellow and white to blue. The Sun’s yellow surface is about 5800K (Kelvin), while some red stars are 3000K and blue stars can have surface temperatures of over 30 000K. When we look up at the stars, they all appear to dazzle bright white, but many stars actuall ...
01 - MrPetersenScience
... _____ 10. How much of the sun’s total mass is composed of hydrogen and helium? a. about 75% b. about 85% c. about 90% d. about 99% _____ 11. The sun’s spectrum reveals that it contains a. almost nothing besides hydrogen. b. traces of almost all chemical elements. c. only hydrogen and helium. d. hydr ...
... _____ 10. How much of the sun’s total mass is composed of hydrogen and helium? a. about 75% b. about 85% c. about 90% d. about 99% _____ 11. The sun’s spectrum reveals that it contains a. almost nothing besides hydrogen. b. traces of almost all chemical elements. c. only hydrogen and helium. d. hydr ...
Astronomy 112: The Physics of Stars Class 11 Notes: Stellar
... contrast, instability occurs when any small deviation from an equilibrium solution tends to drive the system further and further away from it. The classic example of an unstable system is a pencil standing on its point. If one could get the pencil to balance completely perfectly, it would be in equi ...
... contrast, instability occurs when any small deviation from an equilibrium solution tends to drive the system further and further away from it. The classic example of an unstable system is a pencil standing on its point. If one could get the pencil to balance completely perfectly, it would be in equi ...
H-RDiagramSE
... 5. Describe: More than 90 percent of all stars in the universe, including the Sun, are main sequence stars. As main sequence stars age, they move up and to the right on the H-R diagram and become giants or supergiants. Giants and supergiants form when the center of a star collapses and its outer par ...
... 5. Describe: More than 90 percent of all stars in the universe, including the Sun, are main sequence stars. As main sequence stars age, they move up and to the right on the H-R diagram and become giants or supergiants. Giants and supergiants form when the center of a star collapses and its outer par ...
Broad Relativistic Iron Lines from Neutron Star LMXBs
... (2) Probing dense matter: What is the nature of super-dense (5-10 times the nuclear density) degenerate matter (temperature 108 K) at the neutron star core? This is a fundamental problem of physics. Particle colliders (which probe a different regime of temperature/density) cannot answer this quest ...
... (2) Probing dense matter: What is the nature of super-dense (5-10 times the nuclear density) degenerate matter (temperature 108 K) at the neutron star core? This is a fundamental problem of physics. Particle colliders (which probe a different regime of temperature/density) cannot answer this quest ...
Accretion Disk
... still be two stars: a low mass star still burning hydrogen, and a helium proto-white dwarf. The separation will be very small, and the hot core will ionize the ejected envelope, producing a planetary nebula. ...
... still be two stars: a low mass star still burning hydrogen, and a helium proto-white dwarf. The separation will be very small, and the hot core will ionize the ejected envelope, producing a planetary nebula. ...
Radiation feedback in star formation simulations
... ● How do supernovae interact with HII regions and clouds? ● How do supernovae interact with HII regions and clouds? ● Can we explain self-regulation of star formation? ● Can we explain self-regulation of star formation? ● Interaction between observational techniques and simulations ● Interaction bet ...
... ● How do supernovae interact with HII regions and clouds? ● How do supernovae interact with HII regions and clouds? ● Can we explain self-regulation of star formation? ● Can we explain self-regulation of star formation? ● Interaction between observational techniques and simulations ● Interaction bet ...
Astrophysics - Cathkin High School
... and that a small number of all H2 molecules will have a velocity greater than ve , it is not surprising to find that the rate of loss of hydrogen from the Earth’s atmosphere to outer space is considerable. In fact there is very little hydrogen remaining in the atmosphere. Oxygen molecules on the oth ...
... and that a small number of all H2 molecules will have a velocity greater than ve , it is not surprising to find that the rate of loss of hydrogen from the Earth’s atmosphere to outer space is considerable. In fact there is very little hydrogen remaining in the atmosphere. Oxygen molecules on the oth ...
Type II supernova
A Type II supernova (plural: supernovae or supernovas) results from the rapid collapse and violent explosion of a massive star. A star must have at least 8 times, and no more than 40–50 times, the mass of the Sun (M☉) for this type of explosion. It is distinguished from other types of supernovae by the presence of hydrogen in its spectrum. Type II supernovae are mainly observed in the spiral arms of galaxies and in H II regions, but not in elliptical galaxies.Stars generate energy by the nuclear fusion of elements. Unlike the Sun, massive stars possess the mass needed to fuse elements that have an atomic mass greater than hydrogen and helium, albeit at increasingly higher temperatures and pressures, causing increasingly shorter stellar life spans. The degeneracy pressure of electrons and the energy generated by these fusion reactions are sufficient to counter the force of gravity and prevent the star from collapsing, maintaining stellar equilibrium. The star fuses increasingly higher mass elements, starting with hydrogen and then helium, progressing up through the periodic table until a core of iron and nickel is produced. Fusion of iron or nickel produces no net energy output, so no further fusion can take place, leaving the nickel-iron core inert. Due to the lack of energy output allowing outward pressure, equilibrium is broken.When the mass of the inert core exceeds the Chandrasekhar limit of about 1.4 M☉, electron degeneracy alone is no longer sufficient to counter gravity and maintain stellar equilibrium. A cataclysmic implosion takes place within seconds, in which the outer core reaches an inward velocity of up to 23% of the speed of light and the inner core reaches temperatures of up to 100 billion kelvin. Neutrons and neutrinos are formed via reversed beta-decay, releasing about 1046 joules (100 foes) in a ten-second burst. The collapse is halted by neutron degeneracy, causing the implosion to rebound and bounce outward. The energy of this expanding shock wave is sufficient to accelerate the surrounding stellar material to escape velocity, forming a supernova explosion, while the shock wave and extremely high temperature and pressure briefly allow for theproduction of elements heavier than iron. Depending on initial size of the star, the remnants of the core form a neutron star or a black hole. Because of the underlying mechanism, the resulting nova is also described as a core-collapse supernova.There exist several categories of Type II supernova explosions, which are categorized based on the resulting light curve—a graph of luminosity versus time—following the explosion. Type II-L supernovae show a steady (linear) decline of the light curve following the explosion, whereas Type II-P display a period of slower decline (a plateau) in their light curve followed by a normal decay. Type Ib and Ic supernovae are a type of core-collapse supernova for a massive star that has shed its outer envelope of hydrogen and (for Type Ic) helium. As a result, they appear to be lacking in these elements.