# The Sun & Energy Production

1. Apr 1, 2009

1. The problem statement, all variables and given/known data

Using the table that follows, justify dividing the interior of the Sun into two separate functional layers (as regards energy production) and describe the average properties of those two layers.

http://img26.imageshack.us/img26/8356/er3z.jpg [Broken]

2. Relevant equations

R/R0 represents the distance from the center of the Sun in units of solar radii (e.g. R/R0 = 0.5 is halfway out of the Sun).

L/L0 represents the fraction of the solar luminosity produced within the associated distance from the center of the Sun (e.g. 94% of the Sun’s luminosity is created within 0.2 solar radii from the center of the Sun).

M/M0 represents the fraction of the Sun’s mass contained within the associated distance from the center of the Sun (e.g. slightly more than 90% of the Sun’s mass is contained within 0.5 solar radii from the center of the Sun).

Density, g/cm3 represents the density of the Sun expressed in grams per cubic centimeter at that associated radius. Recall the density of water is 1.00 g/cm3, the density of iron is about 8 g/cm3, and the average density of the Sun is 1.4 g/cm3.

T, K represents the temperature of the Sun in Kelvins at the associated radius.

3. The attempt at a solution

Honestly don't know, lol. I'm not even sure what the question is asking.

Last edited by a moderator: May 4, 2017
2. Apr 1, 2009

### Astronuc

Staff Emeritus
It depends on the critierion (criteria), which could be density (> 0.1 or 1 g/cm3), temperature (T > 1E6 K), or energy production (which is a function of density and temperature. There is also a temperature threshold for fusion.

Note that the table gives boundary values, so one has to pick a bounday (or cutoff) and inside is one volume and outside is the other. The inside would be where energy generation occurs, and the outer layer is essentially a layer through which the energy is transmitted.