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ASTRO 7N Exam 2 includes accurate and verified questions covering fundamental astronomy concepts such as the solar system, phases of the Moon, planetary motion, gravity, light and telescopes, and the historical development of astronomical models. Designed for students in introductory astronomy courses such as those offered at Penn State.
for stellar parallax measurements, what is the baseline? - ANSWER-1 AU (average distance between the earth and sun)
the target star appears to move (relative to more distant stars) by an angle times the parallax angle - ANSWER-2x
D = 1/p - ANSWER-D = distance in parsecs p = the parallax angle in arcseconds
How many parsecs away is a star with a measured parallax angle of 0.1 arcsecs? - ANSWER-10 parsecs away. (1/0.1)
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how many parsecs away is a star with a parallax angle of 0.02? - ANSWER-50 parsecs away (1/0.02)
Hertsprung-Russell diagram (H-R diagram) - ANSWER-A graph that plots luminosity v. temperature of stars. The y-axis displays increasing luminosity and the x-axis displays decreasing temperature.
Hertsprung-Russell diagram (H-R diagram) - ANSWER-
H-R Diagram horizontal axis - ANSWER-stars' surface temperature; increasing from left to right
what color are cooler stars? - ANSWER-redder (around 2,300 K)
What color are hotter stars? - ANSWER-bluer (around 40,000 K)
Major spectral classes of stars (run hotter to cooler) - ANSWER-
O - B - A - F - G - K - M
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O - B - A - F - G - K - M - ANSWER-oh be a fine guy kiss me
How is spectral class determined? - ANSWER-using the absorption spectrum, where absorption lines from different chemical elements with different levels of ionization arise at different temperatures
H-R diagram vertical axis - ANSWER-luminosity, expressed in terms of the luminosity of the sun ( "L⊙" )
What is the closest star and how far is it from the sun? - ANSWER-Alpha centauri 4.3 light years (1.35 parsecs) from the sun part of triple star system, with its brightest member similar to sun
Properties of nearest stars - ANSWER-cool dim fall on the lower right of the H-R diagram
What is the brightest star in the nighttime sky? - ANSWER- Sirius the Dog Star
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