008 Lab 06 Summary Key - lab assistance PDF

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Astronomy 115 Summary Questions Lab #6 – Measuring Cosmic Distances 1. List the four standard candles and the maximum distance that can be determined using each standard candle. Main sequence stars – to 100,000 l-y Cepheid variable stars – 100 million l-y White dwarf supernovae – billions of l-y Spiral galaxy’s outer star rotation rate (Tully-Fischer)-billions of l-y

2. What is the one factor that makes white dwarf supernovae a good standard candle for distances to distant galaxies? Since the masses of the white dwarfs are about the same when the supernova occurs, the luminosity of the supernovae are about the same.

3. Star A has a parallax angle of 0.02 second of arc and Star B has a parallax angle of 0.008 second of arc. Both stars have the same apparent brightness. Which star has the greater luminosity and why? Star B has the greater luminosity because it is farther away based on its parallax angle....