# Entropy of a star

1. Aug 22, 2004

### kurious

How is the entropy of a star like the sun or a neutron star calculated?

2. Aug 31, 2004

### meteor

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!

Last edited: Aug 31, 2004
3. Sep 1, 2004

### da_willem

The entropy of a black hole is $$S=\frac{Akc^3}{4hG}$$ where A is the area of the black hole, k the Boltzman's constant, h the Planck's constant, c the speed of light and G the gravitational constant
(http://nrumiano.free.fr/Estars/bh_thermo.html)

I'm not sure you can use the same formula for a (neutron) star though.