The extinction of starlight due to the interstellar medium 
Definitions:
Price Elasticity
The measure of how much the quantity demanded of a good responds to a change in the price of that good, often used to understand the sensitivity of consumers to price changes.
Income Elasticity
Income elasticity measures how the demand for a good or service changes in response to changes in consumer income.
Marginal Utility
The extra pleasure or benefit gained by a consumer from consuming an additional unit of a product or service.
Utility Function
A mathematical representation of how consumers rank different bundles or combinations of goods according to their level of satisfaction.
Q2: A star on the _ generates enough
Q10: The sun makes most of its energy
Q13: The sun has a surface temperature of
Q31: Henrietta Leavitt discovered the period-luminosity relationship for
Q37: _ require(s)that a young hot star
Q39: What distance method is used to calibrate
Q41: Kepler's 2<sup>nd</sup> of planetary motion states that
Q44: The carbon-nitrogen-oxygen cycle<br>A) operates at a slightly
Q45: A star whose parallax is 0.01 seconds
Q50: On the H-R diagram,lines of constant radius