a star produces light & a source of something produces that something ->  stars are a source of light  stars are a source of light & as a source of light becomes closer , the light will appear brighter ->  as the stars become closer, the light of the stars will appear brighter  as the stars become closer, the light of the stars will appear brighter & the sun is the star that is closest to earth -> the sun will be the star that appears the brightest to the earth