Universe
11th Edition
ISBN: 9781319039448
Author: Robert Geller, Roger Freedman, William J. Kaufmann
Publisher: W. H. Freeman
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Chapter 19, Problem 6Q
To determine
The reason for different values of f for the stars with masses lesser than
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The star HD 93250 in the Carina Nebula is a bright O-type star. It has a reported apparent magnitude in the V band of mV = 7.41 and V band absolute magnitude of MV = −6.14.
Using these values calculate the distance to HD 93250 in parsec.
The distance to HD 93250 has been measured by other means as 2350 pc. Compare your calculated value of the distance with the measured value, and give a possible explanation for any difference.
Calculate the value of the interstellar extinction in the V band AV that would account for the difference in the distances.
The parameter E(B − V ) = AB − AV , where AB and AV are the extinctions in the B and V bands, is often used to characterize interstellar extinction. For the star HD 93250 the value E(B − V ) = 0.48 has been measured.
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The B band apparent magnitude of HD 93250 is mB = 8.12. Calculate…
Two stars are identified on the Hertzsprung-Russell diagram below.
Hertzsprung-Russell Diagram
Temperature
(K)
40,000 20,00010,000 7,500 5,500 4,500 3,000
10
10
10
www
10
10
B.
G
K
M
Spectral Class
Based on this diagram, how do the characteristics of Star 1 and Star 2 compare?
Star 1 is cooler and less bright than Star 2.
O Star 1 is hotter and brighter than Star 2.
O Star 1 is cooler and brighter than Star 2.
O Star 1 is hotter and less bright than Star 2.
O Aisoujun
An astronomical image shows two objects that have the same apparent magnitude, i.e., the same brightness. However, spectroscopic follow up observations indicate that while one is a star that is within our galaxy, at a distance dgal away, and has the same luminosity as the Sun, the other is a quasar and has 100x the luminosity of the entire Milky Way galaxy. What is the distance to the quasar? (You may assume, for this rough calculation, that the Milky Way has 1011 stars and that they all have the luminosity as the Sun.) Give your response in Mpc. Value: dgal = 49 pc
Chapter 19 Solutions
Universe
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