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8 Cards in this Set
- Front
- Back
Properties of White Dwarf Stars |
-Is the exposed core of a star that no longer has thermonuclear reactions. -It is supported against the crush of gravity by electron degeneracy pressure -More massive ______ are smaller than less massive ones. -The mass of a _____cannot exceed the Chandrasekhar limit of 1.4 times the mass of the sun. |
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Which Mira is a white dwarf and which is a red giant? |
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What happens when a white dwarf exceeds the 1.4 solar mass white dwarf limit? |
Fusion will start in the carbon core causing a supernova explosion. |
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Properties of a Neutron Star |
- A neutron star is a ball of neutrons created by the collapse of the iron core in a massive star supernova. -It is supported against the crush of gravity by neutron degeneracy pressure. -Typically about 10 km in radius but 300,000 times as massive as the earth. -Neutron stars can spin very rapidly, thereby producing intense magnetic fields |
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Who discovered the first Pulsar in 1967? |
Jocelyn Bell |
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Describe the mass of a neutron star |
-The upper limit on the mass of a neutron star is 3 solar masses. -If the mass is greater than three solar masses then gravity overcomes the neutron degeneracy and the star continues to collapse into an object called a black hole |
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Describe Gravitational Redshift |
The curvature of space-time in Einstein’s general relativity means that clocks run more slowly in stronger gravity. The oscillations of a light wave constitute a type of clock so as a light wave travels away from a large mass, its oscillation frequency becomes smaller and its wavelength becomes longer. |
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Describe the evidence of black holes |
X-Ray binaries are observed in which the mass of the X-Ray emitting source is greater than the 3 solar mass limit of a neutron star. -Rotational rates of the material near the center of a galaxy can only be accounted for by an extremely large mass concentrated at the center of the galaxy. |