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 19, Problem 7Q
To determine
(a)
The main sequence lifetime of
To determine
(b)
The main sequence lifetime of
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= 2000 K and a radius of R,
A young recently formed planet has a surface temperature T
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A star with a radius 1.7 times that of the
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and express your answer in units of the
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%3D
108 m). Choose the option below that
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Select one:
а.
20
O b. 100.
O C.
26.
O d. 5.
O e.
1000
A star has a period of P = 37 days. It has a radius of 5.7 times the radius of the sun.
Calculate it's equatorial speed Vrot.
Answer:
Okm/s Om/s
Check
A star has a radius of 5.7 times the radius of the sun and a mass of 18 times the mass of the sun. It rotates at 0.7 of the critical speed W, the speed at which it's surface at the equator is actually in
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Calculate it's period P.
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Chapter 19 Solutions
Universe: Stars And Galaxies
Ch. 19 - Prob. 1QCh. 19 - Prob. 2QCh. 19 - Prob. 3QCh. 19 - Prob. 4QCh. 19 - Prob. 5QCh. 19 - Prob. 6QCh. 19 - Prob. 7QCh. 19 - Prob. 8QCh. 19 - Prob. 9QCh. 19 - Prob. 10Q
Ch. 19 - Prob. 11QCh. 19 - Prob. 12QCh. 19 - Prob. 13QCh. 19 - Prob. 14QCh. 19 - Prob. 15QCh. 19 - Prob. 16QCh. 19 - Prob. 17QCh. 19 - Prob. 18QCh. 19 - Prob. 19QCh. 19 - Prob. 20QCh. 19 - Prob. 21QCh. 19 - Prob. 22QCh. 19 - Prob. 23QCh. 19 - Prob. 24QCh. 19 - Prob. 25QCh. 19 - Prob. 26QCh. 19 - Prob. 27QCh. 19 - Prob. 28QCh. 19 - Prob. 29QCh. 19 - Prob. 30QCh. 19 - Prob. 31QCh. 19 - Prob. 32QCh. 19 - Prob. 33QCh. 19 - Prob. 34QCh. 19 - Prob. 35QCh. 19 - Prob. 36QCh. 19 - Prob. 37QCh. 19 - Prob. 38QCh. 19 - Prob. 39QCh. 19 - Prob. 40QCh. 19 - Prob. 41QCh. 19 - Prob. 42QCh. 19 - Prob. 43QCh. 19 - Prob. 44QCh. 19 - Prob. 45QCh. 19 - Prob. 46QCh. 19 - Prob. 47QCh. 19 - Prob. 48QCh. 19 - Prob. 49QCh. 19 - Prob. 50QCh. 19 - Prob. 51QCh. 19 - Prob. 52QCh. 19 - Prob. 53Q
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- velocity curve for a double line spectroscopic binary is shown in the sketch. The system is viewed edge-on, i.e., with an inclination angle of i = 90°, so that the maximum possible Doppler shifts for this system are observed. 400 300 So = U, Ani 200 t0 = v Ain i 100 -100 -200 -300 400 O 1 2 3 1 s 1 8: 10 Time (days) Find the orbital period of this binary in days. Doppler Velocity (krn/sec)arrow_forwardA main sequence star of mass 25 M⊙has a luminosity of approximately 80,000 L⊙. a. At what rate DOES MASS VANISH as H is fused to He in the star’s core? Note: When we say “mass vanish '' what we really mean is “gets converted into energy and leaves the star as light”. Note: approximate answer: 3.55 E14 kg/s b. At what rate is H converted into He? To do this you need to take into account that for every kg of hydrogen burned, only 0.7% gets converted into energy while the rest turns into helium. Approximate answer = 5E16 kg/s c. Assuming that only the 10% of the star’s mass in the central regions will get hot enough for fusion, calculate the main sequence lifetime of the star. Put your answer in years, and compare it to the lifetime of the Sun. It should be much, much shorter. Approximate answer: 30 million years.arrow_forwardConsider two stars on the main sequence, A and B. Star A has a mass of 6 M⊙. Star B has a mass of 0.3 M⊙. Compute the ratio of main sequence lifetimes for the two stars, TB/TA .arrow_forward
- velocity curve for a double line spectroscopic binary is shown in the sketch. The system is viewed edge-on, i.e., with an inclination angle of i 90°, so that the maximum possible Doppler shifts for this system are observed. 400 SPo = , Ain i 300 200 l0o = v Ain i 100 -100 -200 -300 400 0 1 2 3 4 10 Time (days) Find the speed of star 2 in km/s. Doppler Velocity (2esu)arrow_forward12: A star with spectral type A0 has a surface temperature of 9600 K and a radius of 2.2 RSun. How many times more luminous is this star than the Sun? (if it is less luminous enter a number less than one) Answer: 36.854 13:This star has a mass of 3.3 MSun. what is the main sequence lifetime of this star? You may assume that the lifetime of the sun is 1010 yr. Please answer question 13 thank you.arrow_forward= A star population is composed of stars with masses in the range between 1M and 150M. The initial mass function is = 0 (M/M)-2.3, where o (Mo). The luminosity of a star = (M/M) 3.3. Calculate the percentage of the total luminosity of the stars in the population which is produced by stars with mass between 120M and 150M. scales with its mass as L/Larrow_forward
- v Correct Part C Which has a greater luminosity, a star with absolute magnitude -2 or a star with absolute magnitude 8 ? O A star with absolute magnitude 8. A star with absolute magnitude -2. Submit Previous Answers Correct Part D By how much? LM=-2 LM-8 000000001 Submit Previous Answers Request Answer X Incorrect; Try Again; 5 attempts remaining Next > Provide Feedback P Pearson 8:58 PM (cp ツ 4/2/202 earson Education Inc. All rights reserved. | Terms of Use Privacy Policy Permissions Contact Us | 49°F Sunnyarrow_forwarda double line The velocity curve for spectroscopic binary is shown in the sketch. The system is viewed edge-on, i.e., with an inclination angle of i = 90°, so that the maximum possible Doppler shifts for this system are observed. 400 U, Aini 300 200 oo - v Ain i 100 -100 -200 -300 400 o 1 2 3 +s 7 8 10 Time (daye) Find the orbital period of this binary in days. Doppler Velocity (2esun)arrow_forward2GM What is the escape velocity (in km/s) from the surface of a 1.6 Mo neutron star? From a 3.0 M. neutron star? (Hint: Use the formula for escape velocity, V. ; 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.) 1.6 Mo neutron star km/s 3.0 Me neutron star km/sarrow_forward
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