Term
What is a heliocentric solar system? |
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Definition
the idea that the planets orbit the central sun in circular orbits |
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Term
Upon whose observations did Kepler base his laws? |
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Definition
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Term
What is the eccentricity of a circle? |
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Definition
how squashed the ellipse is compared to a circle. |
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Term
What are two values needed to describe the size and shape of a planets orbit? |
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Definition
eccentricity and the semi-major axis |
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Term
what is the equation for relating the orbital period and semi-major axis of an orbit? |
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Definition
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Term
What do refracting telescopes use to focus incoming light? |
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Definition
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Term
what do reflecting telescopes use to focus incoming light? |
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Definition
the primary concave mirror |
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Term
What type of objects would a telescope with a focal ratio of 4 best observe? |
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Definition
deep sky objects such as nebulae and galaxies |
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Term
What are LGP and M always compared tO? |
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Definition
the human eye's ability to collect light |
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Term
What are the units of Resolving Power? |
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Definition
D (measured in inches) RP (measured in arcseconds) |
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Term
What is the ideal size of the Exit Pupil? |
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Definition
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Term
What is the definition of a solar rotation rate? |
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Definition
the change in longitude per day |
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Term
What are the units of the solar rotation rate? |
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Definition
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Term
What is the average rotation rate of the sun? |
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Definition
about 13 degrees/per day. (360 degrees/per 27 days) |
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Term
What part of the sun rotates the fastest? |
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Definition
the suns equatorial region rotates faster than the poles |
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Term
What does the absolute magnitude of a star measure? |
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Definition
the actual brightness of the star |
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Term
SPectral types are a measure of what? |
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Definition
of the surface temperatures of stars |
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Term
In which group are most of the stars? |
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Definition
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Term
Red Giants have _____ temperature and _______ luminosity |
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Definition
low temp, high luminosity |
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Term
Fusion reactions take place in the core of the main sequence star. What is hydrogen fusing into? |
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Definition
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Term
When our Sun reaches the end of it's life, what will it become? |
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Definition
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Term
What does the Hubble Law state? |
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Definition
that the recessional velocities of galaxies are directly proportional to their distances |
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Term
What event is theorized to have initiated the expansion of the Universe? |
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Definition
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Term
What is the Hubble constant? |
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Definition
specifies how much velocities of galaxies increase with distance. |
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Term
What important thing does the Hubble constant help us calculate? |
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Definition
the rate in which the universe is expanding. (the age of our universe) |
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