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ASTRONOMY LAB 7-11
FROM PRELABS
25
Astronomy
Undergraduate 2
12/02/2009

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Cards

Term
What is a heliocentric solar system?
Definition
the idea that the planets orbit the central sun in circular orbits
Term
Upon whose observations did Kepler base his laws?
Definition
Tycho Brahe
Term
What is the eccentricity of a circle?
Definition
how squashed the ellipse is compared to a circle.
Term
What are two values needed to describe the size and shape of a planets orbit?
Definition
eccentricity and the semi-major axis
Term
what is the equation for relating the orbital period and semi-major axis of an orbit?
Definition
P^2 infinity A^3
Term
What do refracting telescopes use to focus incoming light?
Definition
the primary convex lens
Term
what do reflecting telescopes use to focus incoming light?
Definition
the primary concave mirror
Term
What type of objects would a telescope with a focal ratio of 4 best observe?
Definition
deep sky objects such as nebulae and galaxies
Term
What are LGP and M always compared tO?
Definition
the human eye's ability to collect light
Term
What are the units of Resolving Power?
Definition
D (measured in inches)
RP (measured in arcseconds)
Term
What is the ideal size of the Exit Pupil?
Definition
7mm
Term
What is the definition of a solar rotation rate?
Definition
the change in longitude per day
Term
What are the units of the solar rotation rate?
Definition
units of degrees per day
Term
What is the average rotation rate of the sun?
Definition
about 13 degrees/per day. (360 degrees/per 27 days)
Term
What part of the sun rotates the fastest?
Definition
the suns equatorial region rotates faster than the poles
Term
What does the absolute magnitude of a star measure?
Definition
the actual brightness of the star
Term
SPectral types are a measure of what?
Definition
of the surface temperatures of stars
Term
In which group are most of the stars?
Definition
the main sequence
Term
Red Giants have _____ temperature and _______ luminosity
Definition
low temp, high luminosity
Term
Fusion reactions take place in the core of the main sequence star. What is hydrogen fusing into?
Definition
helium
Term
When our Sun reaches the end of it's life, what will it become?
Definition
a white dwarf
Term
What does the Hubble Law state?
Definition
that the recessional velocities of galaxies are directly proportional to their distances
Term
What event is theorized to have initiated the expansion of the Universe?
Definition
the Big Bang Theory
Term
What is the Hubble constant?
Definition
specifies how much velocities of galaxies increase with distance.
Term
What important thing does the Hubble constant help us calculate?
Definition
the rate in which the universe is expanding. (the age of our universe)
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