A star with a radius 1.7 times that of the Sun has a surface temperature T=10,000 K. Calculate the luminosity of this star and express your answer in units of the Solar luminosity (the Solar luminosity = 3.84 x 1026 w and the Solar radius = 7 x 108 m). Choose the option below that most closely matches your answer. Select one: а. 20 O b. 100. Ос. 26. O d. 5.

A star with a radius 1.7 times that of the Sun has a surface temperature T=10,000 K. Calculate the luminosity of this star and express your answer in units of the Solar luminosity (the Solar luminosity = 3.84 x 1026 w and the Solar radius = 7 x 108 m). Choose the option below that most closely matches your answer. Select one: а. 20 O b. 100. Ос. 26. O d. 5.

Astronomy

1st Edition

ISBN:9781938168284

Author:Andrew Fraknoi; David Morrison; Sidney C. Wolff

Publisher:Andrew Fraknoi; David Morrison; Sidney C. Wolff

Chapter23: The Death Of Stars

Section: Chapter Questions

Problem 41E: One way to calculate the radius of a star is to use its luminosity and temperature and assume that...

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What are the a) luminosity and b)wavelength of maximum emission for a star with a surface temperature is 2,000K and a size of 1.0*108m?
= 2000 K and a radius of R, A young recently formed planet has a surface temperature T Jupiter radii (where Jupiter's radius is 7 x 107 m). Calculate the luminosity of the planet and 2 determine the ratio of the planet's luminosity to that of the Sun.
12. A star with spectral type MO has a surface temperature of 3750 K and a radius of 0.63 Rsun: How many times more luminous is this star than the Sun? (if it is less luminous enter a number less than one) Answer: Submit All Answers Last Answer: 0.0923 Incorrect, tries 1/5. Hint: Use the Luminosity equation, which says that L is proportional to R^2 T^4. If you keep these as ratios compared to the sun, your L will also come out as a ratio compared to the Sun. This star has a mass of 0.4 Msun- Using the simple approximation that we made in class, what is the main sequence lifetime of this star? You may assume that the lifetime of the sun is 1010 yr. Answer: Submit All Answers Compare this to the lifetime of a MO star listed in Table 22.1 (computed using a more sophisticated approach). Is the value you calculated in the previous problem longer or shorter than what is reported in the table? (L for longer, S for shorter) (You only get one try at this problem.) Answer: Submit All Answers
12: 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.
Using the HR diagram what is the approximate range of relative luminosities covered for a main sequence star at 10 000 K?
"51 Pegasi" is the name of the first normal star (besides the Sun) around which a planet was discovered. It is in the constellation Pegasus the horse. Its parallax is measured to be 0.064 arcsec. a. What is its distance from us? b. The apparent brightness is 1.79 × 10-10 J/(s·m2 ). What is the luminosity? How does that compare with that of the Sun? Look up the temperature: how do
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) 36.854 This star has a mass of 3.3 MSun. Using the simple approximation that we made in class, what is the main sequence lifetime of this star? You may assume that the lifetime of the sun is 1010 yr.
2GM 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/s
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 Sunny
= 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/L
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