20081 Study Guide_77-120
... Similarly, astronomers detect black holes by their gravitational effects on nearby stars, gas, or dust. ...
... Similarly, astronomers detect black holes by their gravitational effects on nearby stars, gas, or dust. ...
Star Classification
... Most stars, including the sun, are "main sequence stars," fueled by nuclear fusion converting hydrogen into helium. For these stars, the hotter they are, the brighter. These stars are in the most stable part of their existence; this stage generally lasts for about 5 billion years. As stars begin to ...
... Most stars, including the sun, are "main sequence stars," fueled by nuclear fusion converting hydrogen into helium. For these stars, the hotter they are, the brighter. These stars are in the most stable part of their existence; this stage generally lasts for about 5 billion years. As stars begin to ...
Test 2, Nov. 17, 2015 - Physics@Brock
... 15. Star S radiates most energy at 400 nanometers and star U radiates most energy at 700 nanometers. From this we can conclude that (a) star S has hotter surface than star U. (b) star S has colder surface than star U. (c) both stars have the same surface temperature. (d) [No comparison of their surf ...
... 15. Star S radiates most energy at 400 nanometers and star U radiates most energy at 700 nanometers. From this we can conclude that (a) star S has hotter surface than star U. (b) star S has colder surface than star U. (c) both stars have the same surface temperature. (d) [No comparison of their surf ...
AST 105: Introduction to the Solar System HOMEWORK # 3
... 5. Would the photons of light leaving a hot star have, on average, a higher or lower energy than those leaving a cooler star? Would a hotter star appear redder or bluer than a colder star? According to Wien’s Law, a hotter star with a higher temperature would have a peak emission at higher frequenci ...
... 5. Would the photons of light leaving a hot star have, on average, a higher or lower energy than those leaving a cooler star? Would a hotter star appear redder or bluer than a colder star? According to Wien’s Law, a hotter star with a higher temperature would have a peak emission at higher frequenci ...
1. Describe (preferably with a sketch) what astronomer
... Polaris has the same surface temperature as the Sun but it is more luminous. b) Polaris’s luminosity is about 10,000 times that of the Sun. How can this be? What must be different about Polaris to make its luminosity 10,000 times that of the Sun? Be quantitative (there should be a number in your ans ...
... Polaris has the same surface temperature as the Sun but it is more luminous. b) Polaris’s luminosity is about 10,000 times that of the Sun. How can this be? What must be different about Polaris to make its luminosity 10,000 times that of the Sun? Be quantitative (there should be a number in your ans ...
Ay 1 – Final Exam
... 18. (2 points) Why is Earth's equilibrium temperature (i.e., the temperature given by setting the luminosity absorbed from the Sun equal to Earth's emitted luminosity) different than the actual average surface temperature we measure for the Earth? Explain the physical mechanism behind this. ...
... 18. (2 points) Why is Earth's equilibrium temperature (i.e., the temperature given by setting the luminosity absorbed from the Sun equal to Earth's emitted luminosity) different than the actual average surface temperature we measure for the Earth? Explain the physical mechanism behind this. ...
Figures I through VII in Section 1 on the following sheet
... List them in order of decreasing temperature (_1_). List them in order of decreasing strength of their Hydrogen lines (_2_). Which spectrum would most likely have been produced by star B from figure X (_3_)? Of stars C and E in figure X, which is more likely to have produced the spectrum in figure I ...
... List them in order of decreasing temperature (_1_). List them in order of decreasing strength of their Hydrogen lines (_2_). Which spectrum would most likely have been produced by star B from figure X (_3_)? Of stars C and E in figure X, which is more likely to have produced the spectrum in figure I ...
Star Classification Lab
... In bold letters, label the following regions of your Hertzsprung-Russell diagram: White Dwarfs, Red Dwarfs, Red Giants, Main Sequence Stars, and Blue Supergiants. ...
... In bold letters, label the following regions of your Hertzsprung-Russell diagram: White Dwarfs, Red Dwarfs, Red Giants, Main Sequence Stars, and Blue Supergiants. ...
Characteristics of Stars
... f. shines brightly in the center of a distant galaxy because of the friction of material spiraling around it ...
... f. shines brightly in the center of a distant galaxy because of the friction of material spiraling around it ...
luminosity1
... • Spectral typing can be used to find the surface temperature of a star. (Along with color and Wien’s Law) • Spectral typing can also be used to find out how much of a given element is in a star. • HD 161817 has much less of all the elements, other than Hydrogen and Helium, than the Sun. • In fact, ...
... • Spectral typing can be used to find the surface temperature of a star. (Along with color and Wien’s Law) • Spectral typing can also be used to find out how much of a given element is in a star. • HD 161817 has much less of all the elements, other than Hydrogen and Helium, than the Sun. • In fact, ...
PHYSICS 113 Practice Questions #2
... b. they lose a significant amount of mass from their outside layers c. their surface temperatures become lower than before d. their overall luminosities increase e. their mass grows significantly as they incorporate planets and interstellar matter near the star 18. Which of the following statements ...
... b. they lose a significant amount of mass from their outside layers c. their surface temperatures become lower than before d. their overall luminosities increase e. their mass grows significantly as they incorporate planets and interstellar matter near the star 18. Which of the following statements ...
A little bit more to do. Stefan
... • Spectral typing can be used to find the surface temperature of a star. (Along with color and Wien’s Law) • Spectral typing can also be used to find out how much of a given element is in a star. • HD 161817 has much less of all the elements, other than Hydrogen and Helium, than the Sun. • In fact, ...
... • Spectral typing can be used to find the surface temperature of a star. (Along with color and Wien’s Law) • Spectral typing can also be used to find out how much of a given element is in a star. • HD 161817 has much less of all the elements, other than Hydrogen and Helium, than the Sun. • In fact, ...
Things to know: This meant as a guide to what you should know. I
... What unusual distortions in time and space are experienced when one moves at speeds near the speed of light? What is gravity in Einstein’s general theory of relativity? What is all matter made of (what are leptons, baryons, quarks)? What is the evidence for the big bang? What is the cosmic microwave ...
... What unusual distortions in time and space are experienced when one moves at speeds near the speed of light? What is gravity in Einstein’s general theory of relativity? What is all matter made of (what are leptons, baryons, quarks)? What is the evidence for the big bang? What is the cosmic microwave ...
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.