20.) Twinkle Twinkle. A stable star of radius R has a mass density profile ρ(r)=α(1−r/R). Here, "stable" means that the star doesn't collapse under its own gravity. If the internal pressure at the core is provided solely by the radiation of photons, calculate the temperature at the core. Assume the star is a perfect black body and treat photons as a classical ideal gas. Use R=7×105 km and α=3 g/cm. Round your answer to the nearest kilokelvin.

20.) Twinkle Twinkle. A stable star of radius R has a mass density profile ρ(r)=α(1−r/R). Here, "stable" means that the star doesn't collapse under its own gravity. If the internal pressure at the core is provided solely by the radiation of photons, calculate the temperature at the core. Assume the star is a perfect black body and treat photons as a classical ideal gas. Use R=7×105 km and α=3 g/cm. Round your answer to the nearest kilokelvin.