= A1. A distant star is determined to have a surface temperature of Tstar - 6000K...
= A1. A distant star is determined to have a surface temperature of Tstar - 6000K and a radius of 5.0 x 108 m. A planet named Hydra is detected orbiting this star at a distance of 1.0 x 1011 m and has an albedo of 0.60. [1] (a) At what wavelength is the peak irradiance from this star? [1] (b) What is the total Luminosity of the star? (c) What is the effective temperature of Hydra? (d) The actual surface temperature of Hydra is 800 K. Briefly explaining this ob- servation using the principles of different transmittance of the atmosphere for short-wave photons and long-wave photon. A diagram may be useful. 3