VbvAstE-001

11.1 The atomic substance
11.1.1 Small bodies
Small celestial bodies - asteroids and satellites of planets - are usually considered as
bodies consisting from atomic matter.
11.1.2 Giants
The transformation of atomic matter into plasma can be induced by action of high
pressure, high temperature or both these factors. If these factors inside a body are
not high enough, atomic substance can transform into gas state. The characteristic
property of this celestial body is absence of electric polarization inside it. If temperature
of a body is below ionization temperature of atomic substance but higher than
its evaporation temperature, the equilibrium equation comes to
− dP
dr = Gγ
r 2 Mr ≈ P R ≈
γ m p
kT
R . (11.1)
Thus, the radius of the body
R ≈ GMmp .
kT
(11.2)
If its mass M ≈ 10 33 g and temperature at its center T ≈ 10 5 K, its radius is
R ≈ 10 2 R ⊙. These proporties are characteristic for giants, where pressure at center
is about P ≈ 10 10 din/cm 2 and it is not enough for substance ionization.
11.2 Plasmas
11.2.1 The non-relativistic non-degenerate plasma. Stars.
Characteristic properties of hot stars consisting of non-relativistic non-degenerate
plasma was considered above in detail. Its EOS is ideal gas equation.
11.2.2 Non-relativistic degenerate plasma. Planets.
At cores of large planets, pressures are large enough to transform their substance into
plasma. As temperatures are not very high here, it can be supposed, that this plasma
can degenerate:
T