Entropy of a Star: Calculating Sun & Neutron Stars

In summary, the entropy of a star like the sun or a neutron star can be calculated using the famous Boltzmann entropy equation S=k*ln W, where W is the number of distinguishable arrangements of atoms/molecules. However, this formula may not be applicable to black holes. The entropy of a black hole is calculated using the formula S=\frac{Akc^3}{4hG}, where A is the area of the black hole, k is Boltzmann's constant, h is Planck's constant, c is the speed of light, and G is the gravitational constant. To calculate the entropy of a fusion reaction in the sun, the power output and the enthalpy and entropy of the reaction can be used
  • #1
kurious
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How is the entropy of a star like the sun or a neutron star calculated?
 
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  • #2
to calculate the thermodynamical entropy, I suppose that you could use the famous Boltzmann entropy equation:
S=k*ln W
W is the number of distinguishable arrangements of atoms/molecules.
If you are able to figure out W, work done!
 
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  • #4
Since we know the power output of the sun and we know the enthalpy and entropy of a fusion reaction, its just an easy ratio.
 

FAQ: Entropy of a Star: Calculating Sun & Neutron Stars

1. What is entropy in the context of stars?

Entropy is a measure of the disorder or randomness of a system. In the context of stars, it refers to the amount of disorder or randomness in the particles and energy within the star.

2. How is the entropy of a star calculated?

The entropy of a star can be calculated using the Sackur-Tetrode equation, which takes into account the mass, temperature, and density of the star.

3. What factors affect the entropy of a star?

The entropy of a star is affected by its mass, temperature, and density. Generally, higher mass and temperature lead to higher entropy, while higher density leads to lower entropy.

4. How does the entropy of the Sun compare to that of a neutron star?

The entropy of the Sun is significantly lower than that of a neutron star. This is because a neutron star is much more massive and dense, leading to a higher level of disorder and randomness.

5. Can the entropy of a star change over time?

Yes, the entropy of a star can change over time as the star goes through different stages of its life. For example, as a star burns through its fuel and evolves into a red giant, its entropy will increase.

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