# Temperature of a planet a distance from sun!

1. Mar 14, 2009

### tetris11

1. The problem statement, all variables and given/known data
Hi,
A spinning shiny red-appearing planet at 130 billion km from the sun, has a diameter of 1700km.
Estimate temperature of planet using simple heat balance equation.
Estimate also the temperature obtained by Wien displacement law.

2. Relevant equations
I've been given no equations, but I know that shiny planets have an Albedo =1, and the wavelength or red = 650nm, which is useful for the Wien law $$\lambda$$=b/T, where T is kelvin and b = 2.9x10^-3

Temp of sun = 5800k

3. The attempt at a solution
I don't know what equation there is to use! I've looked on the internet and gotten this eq.

Tp = Ts((Rs/D^2)^(0.5))

where Tp is temperature of planet, Ts of sun, Rs radius of sun, D distance to planet.
help!

2. Mar 15, 2009

### MathematicalPhysicist

Last edited by a moderator: Apr 24, 2017