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9 Cards in this Set
- Front
- Back
- 3rd side (hint)
distances to galaxies out to 13 million light years is done comparing using lumisoty of what?
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cephid variables (the period-luminosity relationship)
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Think Hubble/Shapley
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distances of galaxies out to 82 million light years is done measureing lumisoty of what?
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bright O and B stars. They have an upward limit of lumisoty...so find the brightest one in the galaxy.
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we can see them in the galaxies in Big Dipper.
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Beyond 82 millio light years, we use what to determine distance to galaxies?
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Supergiant spirals, with small nuclei. They have absolute magnitude of -21. (i.e., M 101).
We also use red shift. |
2 things.
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brightest blue supergiants in large spiral galaxies have absolute magnitude of about what?
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-10
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Milky way galaxy has a nucleus of what color stars?
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reddish
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Milkyway galaxy has spiral arms of what color stars?
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bluish
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Three basic types of galaxies, smallest to largest:
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irregular, elliptical, spiral
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magelanic clouds, big round blobs, Andromeda
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our sun is how many lr from center?
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33,000 lyrs
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sun circuits galaxy in how many years
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2.4 x 10(8)
or 240 million years (i thought it was closer to 300 mill). |
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