UNIVERSE (LOOSELEAF):STARS+GALAXIES
6th Edition
ISBN: 9781319115043
Author: Freedman
Publisher: MAC HIGHER
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Chapter 20, Problem 63Q
To determine
Thedistance to
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For the PP chain 0.7% of the mass participating in nuclear fusion is liberated as energy which
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Using these values calculate the distance to HD 93250 in parsec.
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As we have discussed, Sirius B in the Sirius binary system is a white dwarf with MB ∼ 1M , LB ∼ 0.024L ,and rB ∼ 0.0084r . For such a white dwarf, the temperature at the center is estimated to be ∼ 107 K.If Sirius B’s luminosity were due to hydrogen fusion, what is the upper limit of the mass fraction of thehydrogen in such a white dwarf?Step 1: Calculate the observed energy production rate per unit mass (remember luminosity is energy outputper unit time).Step 2: Use the per unit mass energy generation rate of hydrogen fusion (via PP chain) to estimate thepossible hydrogen mass fraction given the condition at the center of the white dwarf.
Chapter 20 Solutions
UNIVERSE (LOOSELEAF):STARS+GALAXIES
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