help with these questions
Compare the brightness of venus which has an apparent magnitude (m)of -4.6 to a full moon, which has an apparent magnitude of -12.7
The star Sirius has a magnitude of -1.6, and the star costor has a magnitude of 1.6. what is the ratio of their brightness ;
The star vega is 24×1014 km away from earth . what the distance in light years