Sample Stellar Evolution TEST QUESTIONS
... 10. Hydrostatic equilibrium refers to the balance between weight and pressure. 11. The Orion region contains young main sequence stars and an emission nebula. 12. The thermal motions of the atoms in a gas cloud can make it collapse to form a protostar. 13. The pressure of a gas generally depends on ...
... 10. Hydrostatic equilibrium refers to the balance between weight and pressure. 11. The Orion region contains young main sequence stars and an emission nebula. 12. The thermal motions of the atoms in a gas cloud can make it collapse to form a protostar. 13. The pressure of a gas generally depends on ...
Homework #8 1. Problem 10.21 2. The Origin of the Main Sequence
... f) Imagine that at any fixed temperature T nuclear energy generation were less efficient than it is by a factor of 100 (e.g., because of a smaller probability of tunneling through the Coulomb barrier). For a star of a given mass M determine whether the luminosity, radius, central temperature, and ef ...
... f) Imagine that at any fixed temperature T nuclear energy generation were less efficient than it is by a factor of 100 (e.g., because of a smaller probability of tunneling through the Coulomb barrier). For a star of a given mass M determine whether the luminosity, radius, central temperature, and ef ...
GEARS Workshop Monday - Georgia Southern University
... our own Sun, have found a remarkable object where the nuclear reactor that once powered it has only just shut down. This star, the hottest known white dwarf, H1504+65, seems to have been stripped of its entire outer regions during its death throes leaving behind the core that formed its power plant. ...
... our own Sun, have found a remarkable object where the nuclear reactor that once powered it has only just shut down. This star, the hottest known white dwarf, H1504+65, seems to have been stripped of its entire outer regions during its death throes leaving behind the core that formed its power plant. ...
PS 224, Fall 2014 HW 4
... a: Dark cloud: Large molecular clouds develop dense regions that appear darker than surrounding regions. This can be precipitated by external pressure or forces or random fluctuations present in the cloud. These regions are very large, typically around 200,000 AU. b: Gravitational collapse: When the ...
... a: Dark cloud: Large molecular clouds develop dense regions that appear darker than surrounding regions. This can be precipitated by external pressure or forces or random fluctuations present in the cloud. These regions are very large, typically around 200,000 AU. b: Gravitational collapse: When the ...
Reach_for_the_stars_final_questions.doc
... 6. Antares emits a large portion of its energy in what non-visible wavelength? (1 pt) _____________________________________________________________________________________________________ 7. White dwarfs can go supernova when they approach a certain mass. What is the name of this “critical mass”? (1 ...
... 6. Antares emits a large portion of its energy in what non-visible wavelength? (1 pt) _____________________________________________________________________________________________________ 7. White dwarfs can go supernova when they approach a certain mass. What is the name of this “critical mass”? (1 ...
Cannibal star? - NRC Publications Archive
... engulfed them. On Earth it took 300 million years for the first living creatures to appear. We still have about four billion years before the Sun becomes a red giant. Earth will be engulfed, but Mars may not. With 12 times the mass of the Sun and about 10 billion times the volume, Betelgeux is far l ...
... engulfed them. On Earth it took 300 million years for the first living creatures to appear. We still have about four billion years before the Sun becomes a red giant. Earth will be engulfed, but Mars may not. With 12 times the mass of the Sun and about 10 billion times the volume, Betelgeux is far l ...
Mr. Scharff
... Introduction. The Hertzsprung-Russell diagram is actually a graph that illustrates the relationship that exists between the average surface temperature of stars and their absolute magnitude, which is how bright they would appear to be if they were al the same distance away. Rather than speak of the ...
... Introduction. The Hertzsprung-Russell diagram is actually a graph that illustrates the relationship that exists between the average surface temperature of stars and their absolute magnitude, which is how bright they would appear to be if they were al the same distance away. Rather than speak of the ...
Question: Fossilized footprints of Coelophysis
... boundary between Earth’s mantle and core? Key words: temperature, mantle, core, star Picking the right table: The Inferred Properties of Earth’s Interior table (p. NY28) has a diagram of Earth’s interior, along with graphs that show how pressure and temperature change with depth. From this table, yo ...
... boundary between Earth’s mantle and core? Key words: temperature, mantle, core, star Picking the right table: The Inferred Properties of Earth’s Interior table (p. NY28) has a diagram of Earth’s interior, along with graphs that show how pressure and temperature change with depth. From this table, yo ...
PHYS-633: Problem set #2
... b. Now using the energy release efficiency ≈ 0.007 for H burning to He, compute the associated rates of reduction dMH /dt in the mass of Hydrogen in the sun. Again give your answer in kg/s and M /yr. c. Now compute the total decrease in the mass of solar H (in units of M ) over its main sequence ...
... b. Now using the energy release efficiency ≈ 0.007 for H burning to He, compute the associated rates of reduction dMH /dt in the mass of Hydrogen in the sun. Again give your answer in kg/s and M /yr. c. Now compute the total decrease in the mass of solar H (in units of M ) over its main sequence ...
Astronomy Notes: Deep Space
... star’s TRUE brightness compared to the sun: big stars are bright, dwarf stars are dim. Composition of the star: Spectra tells us that, because each element has its own spectral fingerprint. http://www.astro.ubc.ca/~scharein/a311/Sim/hr/HRdiagram.html http://en.wikipedia.org/wiki/List_of_largest_know ...
... star’s TRUE brightness compared to the sun: big stars are bright, dwarf stars are dim. Composition of the star: Spectra tells us that, because each element has its own spectral fingerprint. http://www.astro.ubc.ca/~scharein/a311/Sim/hr/HRdiagram.html http://en.wikipedia.org/wiki/List_of_largest_know ...
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.