12.A star with spectral type MO has a surface temperature of 3750 K and a radius of 0.63 Rsun: How manytimes 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: 0.0923Incorrect, tries 1/5.Hint: Use the Luminosity equation, which says that L is proportional to R^2 T^4. If you keep these asratios 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 themain sequence lifetime of this star? You may assume that the lifetime of the sun is 1010 yr.Answer:Submit All AnswersCompare this to the lifetime of a MO star listed in Table 22.1 (computed using a more sophisticatedapproach). Is the value you calculated in the previous problem longer or shorter than what is reportedin the table? (L for longer, S for shorter) (You only get one try at this problem.)Answer:Submit All Answers

Given: The surface temperature of the star T1 = 3750 K. The radius of the star R1 = 0.63 Rsun.

Answered: 12. A star with spectral type MO has a…

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