Astronomy question: estimate life expectancy?

Given that the Sun's lifetime is about 10 billion years, estimate the life expectancy of

(a) 0.2-solar mass, 0.01-solar luminosity red dwarf.

Could you please solve and explain this for me?

Update:

Oh, well can you tell me if my answer is right?

If stellar lifetime = stellar mass/stellar luminosity.

0.2/0.01 = 20

So its has a life span 20 times that of the sun?

10 billion x 20 = 200billion

1 Answer

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  • Tara
    Lv 4
    8 years ago
    Favorite Answer

    E = M^{-2.5}

    =0.2^-2.5

    =55.9016994375

    life time=0.2/0.01 = 20

    life span 20 times that of the sun

    10 billion x 20 = 200billion

    so you are correct

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