Formation of Stars
... Clouds and nebula • The interstellar medium is not uniform, but varies by large factors in density and temperature. • The clumps in the interstellar medium are clouds or nebulae (one nebula, two nebulae). • Three types of nebulae: – Emission nebulae: photons strike atoms and excite electrons to hig ...
... Clouds and nebula • The interstellar medium is not uniform, but varies by large factors in density and temperature. • The clumps in the interstellar medium are clouds or nebulae (one nebula, two nebulae). • Three types of nebulae: – Emission nebulae: photons strike atoms and excite electrons to hig ...
The HR Diagram - Faculty Web Pages
... squeeze the gas all down to a single point, and radiation pressure, which wants to blast all the gas out to infinity. These two opposite forces balance out in a process called Hydrostatic Equilibrium, and keep the gas at a stable, fairly constant size. The radiation itself is due to the fusion of pr ...
... squeeze the gas all down to a single point, and radiation pressure, which wants to blast all the gas out to infinity. These two opposite forces balance out in a process called Hydrostatic Equilibrium, and keep the gas at a stable, fairly constant size. The radiation itself is due to the fusion of pr ...
ASTRONOMY 301 EXAMPLES OF TEST
... 33. Suppose that your eyes were sensitive only to the infrared light given off by normal furniture at room temperature. Which of these statements would be wrong? (A) If you dove into a swimming pool full of water and opened your eyes under water, you would see the Sun as a brilliant light above the ...
... 33. Suppose that your eyes were sensitive only to the infrared light given off by normal furniture at room temperature. Which of these statements would be wrong? (A) If you dove into a swimming pool full of water and opened your eyes under water, you would see the Sun as a brilliant light above the ...
Transcript - Chandra X
... source. The notes may be used during both parts of the event. Some regional and/or state competitions may use a planetarium or star dome. Coaches should contact their state directors for this information; if this type of venue is used, teams will need to provide clipboards and red lights for the eve ...
... source. The notes may be used during both parts of the event. Some regional and/or state competitions may use a planetarium or star dome. Coaches should contact their state directors for this information; if this type of venue is used, teams will need to provide clipboards and red lights for the eve ...
1.3 Accretion power in astrophysics
... It can be seen that written in this form is the efficiency of conversion of the rest mass energy of the accreted matter into heat . According to the above calculation, the efficiency of energy conversion simply depends upon how compact the star is. Thus , accretion is a powerful source of energy ...
... It can be seen that written in this form is the efficiency of conversion of the rest mass energy of the accreted matter into heat . According to the above calculation, the efficiency of energy conversion simply depends upon how compact the star is. Thus , accretion is a powerful source of energy ...
1:45 PM TuTh This is a one-quarter course on
... has some familiarity with basic scientific concepts and reasoning. Elementary calculus will some times be used in classroom derivations because, for those understanding calculus, it is the easiest and clearest way of obtaining results. It is not expected, however, that the student will need to use c ...
... has some familiarity with basic scientific concepts and reasoning. Elementary calculus will some times be used in classroom derivations because, for those understanding calculus, it is the easiest and clearest way of obtaining results. It is not expected, however, that the student will need to use c ...
Slide 1 - Arif Solmaz
... • Neutron stars are very dense, spin rapidly, and have intense magnetic fields. • Neutron stars may appear as pulsars due to the lighthouse effect. • A neutron star in a close binary may become an X-ray burster or a millisecond pulsar. ...
... • Neutron stars are very dense, spin rapidly, and have intense magnetic fields. • Neutron stars may appear as pulsars due to the lighthouse effect. • A neutron star in a close binary may become an X-ray burster or a millisecond pulsar. ...
The HR Diagram - Faculty Web Pages
... squeeze the gas all down to a single point, and radiation pressure, which wants to blast all the gas out to infinity. These two opposite forces balance out in a process called Hydrostatic Equilibrium, and keep the gas in a stable, fairly constant-sized sphere. The radiation itself is due to the fusi ...
... squeeze the gas all down to a single point, and radiation pressure, which wants to blast all the gas out to infinity. These two opposite forces balance out in a process called Hydrostatic Equilibrium, and keep the gas in a stable, fairly constant-sized sphere. The radiation itself is due to the fusi ...
Light and Spectroscopy Concept Inventory
... marked in the drawing. By comparing the positions of the lines in the spectrum to a known laboratory spectrum on Earth, which of the following properties of the nebula can be directly determined? a. Motion towards or away from Earth only. b. Temperature only. c. Chemical composition (type of atoms) ...
... marked in the drawing. By comparing the positions of the lines in the spectrum to a known laboratory spectrum on Earth, which of the following properties of the nebula can be directly determined? a. Motion towards or away from Earth only. b. Temperature only. c. Chemical composition (type of atoms) ...
Chapter 13 Neutron Stars and Black Holes
... • Neutron stars are very dense, spin rapidly, and have intense magnetic fields • Neutron stars may appear as pulsars due to lighthouse effect • Neutron star in close binary may become X-ray burster or millisecond pulsar • Gamma-ray bursts probably are due to two neutron stars colliding, or to hypern ...
... • Neutron stars are very dense, spin rapidly, and have intense magnetic fields • Neutron stars may appear as pulsars due to lighthouse effect • Neutron star in close binary may become X-ray burster or millisecond pulsar • Gamma-ray bursts probably are due to two neutron stars colliding, or to hypern ...
The Stars education kit - Student activities 5-10
... expanding and contracting periodically. Astronomers can use the period of the star (or the time it takes to vary) and its luminosity to measure the distance to the star. The nuclear fusion reactions continue until all the helium in the core has been converted to carbon and oxygen. The nuclear reacti ...
... expanding and contracting periodically. Astronomers can use the period of the star (or the time it takes to vary) and its luminosity to measure the distance to the star. The nuclear fusion reactions continue until all the helium in the core has been converted to carbon and oxygen. The nuclear reacti ...
ph507lecnote06
... Main sequence stars with mass larger than about 8 MSun eventually form white dwarf stars with masses larger than the Chandrasekhar limit and collapse. ...
... Main sequence stars with mass larger than about 8 MSun eventually form white dwarf stars with masses larger than the Chandrasekhar limit and collapse. ...
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 ...
astronomy - Scioly.org
... A. as the radius decreases, the temperature decreases and the opacity increases. B. as the radius decreases, the temperature and opacity increase. C. as the radius decreases, the temperature increases and the opacity decreases. D. as the radius decreases, the temperature and opacity decrease. 26. In ...
... A. as the radius decreases, the temperature decreases and the opacity increases. B. as the radius decreases, the temperature and opacity increase. C. as the radius decreases, the temperature increases and the opacity decreases. D. as the radius decreases, the temperature and opacity decrease. 26. In ...
educator guide - Michigan Science Center
... visible surface of the sun. We have monitored this portion of the Sun for sunspots, cooler darker regions on the surface, for hundreds of years. Sunspots remain one of the most accurate ways of monitoring solar activity. The convective zone is just what it sounds, the layer where convection currents ...
... visible surface of the sun. We have monitored this portion of the Sun for sunspots, cooler darker regions on the surface, for hundreds of years. Sunspots remain one of the most accurate ways of monitoring solar activity. The convective zone is just what it sounds, the layer where convection currents ...
Luminosity
... B) show few absorption lines? 1. Many elements have been used up in these stars 2. These stars are old and were formed before there were many elements in the galaxy 3. Many atoms in these stars are ionized–have lost electrons–so can’t absorb 4. Much of their absorption is in the ultraviolet 5. 3 and ...
... B) show few absorption lines? 1. Many elements have been used up in these stars 2. These stars are old and were formed before there were many elements in the galaxy 3. Many atoms in these stars are ionized–have lost electrons–so can’t absorb 4. Much of their absorption is in the ultraviolet 5. 3 and ...
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.