Is the radiation zone dense?
Is the radiation zone dense?
The radiative zone is a thick layer of highly ionized, very dense gases which are under constant bombardment by the gamma rays from the core. It is about 75% hydrogen and 24% helium.
What is the radiative zone in a star?
[ rā′dē-ə-tĭv ] The layer of a star that lies just outside the core, to which radiant energy is transferred from the core in the form of photons. In this layer, photons bounce off other particles, following fairly random paths until they enter the convection zone.
What is the radiation zone of the earth?
A radiation zone, or radiative region is a layer of a star’s interior where energy is primarily transported toward the exterior by means of radiative diffusion and thermal conduction, rather than by convection. Energy travels through the radiation zone in the form of electromagnetic radiation as photons.
What is happening in the radiative zone?
Within the radiative zone, the solar material is hot and dense enough that thermal radiation transfers the heat of the core outward through the Sun. The core of the Sun is where nuclear fusion reactions are happening – protons are merged together to create atoms of helium.
What is the density of the radiative zone?
The Radiative Zone. The density drops from 20 g/cm³ (about the density of gold) down to only 0.2 g/cm³ (less than the density of water) from the bottom to the top of the radiative zone. The temperature falls from 7,000,000° C to about 2,000,000° C over the same distance.
Which is the radiation zone of the Sun?
In the Sun, the region between the solar core at 0.2 of the Sun’s radius and the outer convection zone at 0.71 of the Sun’s radius is referred to as the radiation zone, although the core is also a radiative region. The convection zone and the radiation zone are divided by the tachocline, another part of the Sun.
How is the radiation zone stable against convection?
The radiation zone is stable against formation of convection cells if the density gradient is high enough, so that an element moving upwards has its density lowered (due to adiabatic expansion) less than the drop in density of its surrounding, so that it will experience a net buoyancy force downwards. The criterion for this is:
How big is the radiation zone of a star?
From 0.3 to 1.2 solar masses, the region around the stellar core is a radiation zone, separated from the overlying convection zone by the tachocline. The radius of the radiative zone increases monotonically with mass, with stars around 1.2 solar masses being almost entirely radiative.