The Sun has a luminosity of W. What is the flux density from the Sun at Neptune, a distance of 30.1 AU away from the Sun? Use a value of m for the length of 1 AU. Give your answer to two decimal places.
Star A has a luminosity and star has a luminosity . At a distance away from star and a distance away from star , the flux densities due to each star are equal. What is the ratio ?
The Peony star, which is located near the galactic center, has a luminosity of . At what distance from this star is the flux density equal to the flux density from the Sun at Earth? Use a value of m for the length of 1 AU and W for the luminosity of the Sun. Give your answer in scientific notation to two decimal places in astronomical units.