The Sun has an expected main-sequence lifetime of about 10¹⁰ years.What is the lifetime on the main sequence of a 2 solar mass star?
A)1.8×10⁶ years
B)1.8×10⁹ years
C)1.8×10¹⁰ yearsα
D)1.8×10¹¹ years

Question

Quizplus · Accepted Answer

The main-sequence lifetime of a star depends on its mass. The more massive the star, the shorter its main-sequence lifetime. The lifetime can be calculated using the mass-luminosity relation, which relates a star's mass to its luminosity and temperature. For a 2 solar mass star, its main-sequence lifetime is expected to be about 1.8×10⁹ years, which is much shorter than the Sun's lifetime of 10¹⁰ years. Therefore, the best choice is B.

The Sun Has an Expected Main-Sequence Lifetime of About 10¹⁰