Please define your variables.quasarLie said:F=L/4πD²
What is the contribution of the reflected light to the temperature?quasarLie said:how to use the albedo
It ought to say a bit more... like, assume the planet rotates on its axis sufficiently fast and has sufficient atmosphere (but no greenhouse gases) that the temperature can be assumed roughly equal over the whole surface. Otherwise the answer can be substantially different.quasarLie said:consider a planet in a circular orbit around a star... calculate the average temperature
The planet don't have an atmosphere and it's luminosity is 2/3L (sun). I don't have more informationharuspex said:Please define your variables.
What is the contribution of the reflected light to the temperature?
Edit:
It ought to say a bit more... like, assume the planet rotates on its axis sufficiently fast and has sufficient atmosphere (but no greenhouse gases) that the temperature can be assumed roughly equal over the whole surface. Otherwise the answer can be substantially different.
if you are told that then you should have included it in the problem statement.quasarLie said:The planet don't have an atmosphere
To calculate the average temperature, we need to use the equation for the effective temperature of a planet: Te = [ (1 - A) * S * (1 - α) / 4σ ]^(1/4), where Te is the effective temperature, A is the albedo, S is the solar constant, α is the greenhouse factor, and σ is the Stefan-Boltzmann constant. We can plug in the values for the given parameters and solve for Te to get the average temperature.
The solar constant is a measure of the amount of solar radiation that reaches the outer atmosphere of a planet. It is influenced by the distance between the planet and its star, as well as the star's luminosity. The solar constant plays a crucial role in determining the average temperature of a planet, as it is used in the calculation of the effective temperature.
The albedo of a planet represents the percentage of incoming solar radiation that is reflected back into space. A higher albedo means more radiation is reflected, leading to lower temperatures. In this scenario, with an albedo of 30%, the planet would have a lower average temperature compared to a planet with a lower albedo.
The greenhouse factor takes into account the effects of the atmosphere on trapping heat and influencing the temperature of a planet. It represents the percentage of incoming solar radiation that is absorbed and re-emitted by the atmosphere. In our calculation, a value of 0 for the greenhouse factor would mean that the atmosphere has no effect on the temperature, while a value of 1 would mean that the atmosphere is completely opaque and all the radiation is trapped, leading to a higher average temperature.
While the given information is sufficient to make an estimate of the average temperature of the planet, it may not be completely accurate. Other factors such as the composition of the planet's atmosphere, its rotation rate, and any internal heat sources can also influence the temperature. In order to get a more precise calculation, more data and a more complex model would be required.