Term
| the milky way galaxy's shape and components |
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Definition
| flat disk with spiral arms surrounding a central bulge, with a roughly spherical halo surrounding everything |
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Term
star motions in the milky way galaxy?
(think of the components of the galaxy) |
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Definition
disk stars- orbit the galaxy's center in orderly circles that all go in the same direction bobbing slightly up and down as they orbit
halo and bulge stars-swoop high above and below the disk on randomly oriented orbits |
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Term
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Definition
| interstellar gas and sit fill the galactic disk, obscuring our view when we look through it |
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Term
| what are the milky way's spiral arms |
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Definition
| waves of stars formation that spread through our galaxy's disk. New stars |
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Term
| What evidence do we have for a massive black hole? |
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Definition
| stars close to our galaxy's center orbit a nearly invisible and tiny object about 4 million times as massive as our sun. |
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