Term
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Definition
| The total mass of the star must equal the sum of the masses in its shells. Of course, no shell can be empty, and there is no such thing as a negative mass |
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Term
| Conservation of Energy Law |
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Definition
| says the amount of energy flowing out of the top of a shell in the star must be equal to the amount of energy coming in at the bottom of the shell pluss whatever energy is generated within the shell |
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Term
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Definition
| the weight on each layer is balanced by the pressure in that layer |
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Term
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Definition
| Energy moves from hot to cool by radiation, convection, or conduction |
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Term
| Zero-Age main sequence (ZAMS) |
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Definition
| Once nuclear fusion of hydrogen becomes the dominant energy production process and the excess energy gained from gravitational contraction has been lost,[14] the star lies along a curve on the Hertzsprung-Russell diagram (or HR diagram) called the standard main sequence |
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Term
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Definition
| When a gas is so dense that the electrons are not free to change their energy |
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Term
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Definition
| 100 million Kelvin He nuclei fuse together to form Carbon - thus three He nuclei (alpha particles) He fusion is triple alpha process |
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Term
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Definition
| Start He fusion with an explosion is caused by the density of the He core which can reach 1,000,000 g/cm^3 |
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Term
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Definition
1:) Open and Globular look different but evolve the same
2:) Estimate the age of a cluster by oberving the turnoff point
3:) Compare the stars and see how they are different |
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Term
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Definition
| changes its brightness in a periodic way |
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Term
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Definition
| more or less luminous because of an internal process |
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Term
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Definition
| Cepheid variables are supergiants or bright giant stars of spectral type F or G, complete cycle in 2-60 days |
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Term
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Definition
| star with a period of less than one day |
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Term
| Period Luminosity Relation |
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Definition
Longer Period cephid 40,000 time brighter
Shorter Period only 100's of times brighter |
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Term
| Period Luminosity Relation |
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Definition
Longer Period cephid 40,000 time brighter
Shorter Period only 100's of times brighter |
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Term
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Definition
| The region where size and temperataure lead to pulsation on the HR diagram |
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Term
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Definition
| The region where size and temperataure lead to pulsation on the HR diagram |
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Term
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Definition
| The region where size and temperataure lead to pulsation on the HR diagram |
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Term
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Definition
| The region where size and temperataure lead to pulsation on the HR diagram |
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Term
| Period Luminosity Relation |
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Definition
Longer Period cephid 40,000 time brighter
Shorter Period only 100's of times brighter |
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Term
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Definition
| The region where size and temperataure lead to pulsation on the HR diagram |
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