Concept explainers
(a)
The energy flux at the surface of Sirius, if the bright star Sirius in the constellation of Canis Major has a radius of
(a)
Answer to Problem 26Q
Solution:
Explanation of Solution
Given data:
The bright star Sirius in the constellation of Canis Major has a radius of
The luminosity is
Formula used:
Write the expression for energy flux of the Sun’s luminosity
Here,
Explanation:
Recall the expression for energy flux of the Sun’s luminosity
The bright star Sirius in the constellation of Canis Major has a radius of
The luminosity is about
The relation between flux and luminosity of the different stars is:
Substitute
Refer to Box 5-2 for the value of the energy flux of the Sun’s luminosity.
Substitute
Conclusion:
The energy flux at the surface of Sirius is
(b)
The surface temperature of Sirius. Also compare the value with that given in Box 5-2, if the bright star Sirius in the constellation of Canis Major has a radius of
(b)
Answer to Problem 26Q
Solution:
Explanation of Solution
Given data:
The bright star Sirius in the constellation of Canis Major has a radius of
The luminosity is
Formula used:
The expression for Stefan Boltzmann law is:
Here,
Explanation:
Recall the result of part (a).
The expression for Stefan Boltzmann law is:
Substitute
Refer to Box 5-2 for the value of the surface temperature of the Sun.
The surface temperature of Sirius is very high as compared to the surface temperature of the Sun.
Conclusion:
The surface temperature of Sirius is
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Chapter 5 Solutions
Universe
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