Question

When we talk about the temperature, luminosity, and chemical composition of the sun, what particular layer of the sun are we talking about?

Answer 1

When we talk about the temperature, luminosity, and chemical composition of the sun, we are talking about the solar photosphere, which is the outer layer of the Sun. It is the layer we can see with our eyes.

Inner layers

Below the photosphere are layers described as the Convection Zone, the Radiative Zone, and the Core. These are characterized by their different modes of heat transfer. The core is where fusion processes take place, converting hydrogen to helium and heavier elements. Heat generated by that process is radiated outward through the Radiative Zone to the Convection Zone where heat transfer takes place mainly by convection.

Photosphere

When the energy produced by the fusion processes finally reaches the surface, it is emitted in the form of light and heat (electromagnetic radiation) as well as energetic matter, the "solar wind".

The photosphere is characterized by its temperature (approximately 5,700K), luminosity (approximately 4x10^26 W), and chemical composition (mostly Hydrogen and Helium).

Answer 2

We are talking about the core layer of the sun when we discuss the temperature, luminosity, and chemical composition of the sun. The core is located at the center of the sun and is responsible for producing most of the heat and light we receive. It has an extremely high temperature, estimated to be around 15 million Kelvin, and is composed of mostly hydrogen and helium. The core also has a high luminosity, meaning it produces a large amount of energy.