Universe: Stars And Galaxies
6th Edition
ISBN: 9781319115098
Author: Roger Freedman, Robert Geller, William J. Kaufmann
Publisher: W. H. Freeman
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Chapter 18, Problem 14Q
To determine
To compare:
Barnard objects and Bok globules.
The number of Sun-sized stars that could be made from a Barnardobject.
The number of Sun-sized stars that could be made froma Bok globule.
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A. Estimate the surface gravity of a neutron star with R = 10 km and M = 2M. .
B. Determine the density of such a neutron star in g/cm³.
C. How much would a teaspoon (5 cm³) of this neutron star weigh on Earth? This
material is known as neutronium. Give your answer in pounds.
D. Which would be heavier: a teaspoon of neutronium weighed on Earth, or a teaspoon
of water weighed on the surface of a neutron star?
All massive main sequence stars reside in clouds of glowing gas. The four powerful stars in the center of the Orion Nebula are good examples. Lower mass stars like the Sun generally don't have clouds of gas around them. a. Why do powerful stars reside in gas clouds? b. What is making the gas glow exactly? For the last question, refer to the surface temperature of these stars, and to Wien's Law.
What is the escape velocity (in km/s) from the surface of a 1.1 M. neutron star? From a 3.0 M. neutron star? (Hint: Use the formula for escape velocity, V̟ = V
2GM
; make sure to
express quantities in units of meters, kilograms, and seconds. Assume a neutron star has a radius of 11 km and assume the mass of the Sun is 1.99 x 1030
kg.)
1.1 M neutron star
km/s
3.0 M. neutron star
km/s
If a neutron star has a radius of 12 km and a temperature of 8.0 x 10° K, how luminous is it? Express your answer in watts and also in solar luminosity units. (Hint: Use the relation
Use 5,800 K for the surface temperature of the Sun. The luminosity of the Sun is 3.83 x 1026 w.)
luminosity in watts
luminosity in solar luminosity units
Chapter 18 Solutions
Universe: Stars And Galaxies
Ch. 18 - Prob. 1QCh. 18 - Prob. 2QCh. 18 - Prob. 3QCh. 18 - Prob. 4QCh. 18 - Prob. 5QCh. 18 - Prob. 6QCh. 18 - Prob. 7QCh. 18 - Prob. 8QCh. 18 - Prob. 9QCh. 18 - Prob. 10Q
Ch. 18 - Prob. 11QCh. 18 - Prob. 12QCh. 18 - Prob. 13QCh. 18 - Prob. 14QCh. 18 - Prob. 15QCh. 18 - Prob. 16QCh. 18 - Prob. 17QCh. 18 - Prob. 18QCh. 18 - Prob. 19QCh. 18 - Prob. 20QCh. 18 - Prob. 21QCh. 18 - Prob. 22QCh. 18 - Prob. 23QCh. 18 - Prob. 24QCh. 18 - Prob. 25QCh. 18 - Prob. 26QCh. 18 - Prob. 27QCh. 18 - Prob. 28QCh. 18 - Prob. 29QCh. 18 - Prob. 30QCh. 18 - Prob. 31QCh. 18 - Prob. 32QCh. 18 - Prob. 33QCh. 18 - Prob. 34QCh. 18 - Prob. 35QCh. 18 - Prob. 36QCh. 18 - Prob. 37QCh. 18 - Prob. 38QCh. 18 - Prob. 39QCh. 18 - Prob. 40QCh. 18 - Prob. 41QCh. 18 - Prob. 42QCh. 18 - Prob. 43QCh. 18 - Prob. 44QCh. 18 - Prob. 45QCh. 18 - Prob. 46QCh. 18 - Prob. 47QCh. 18 - Prob. 48QCh. 18 - Prob. 49Q
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