Astronomy Problems: Please Help! THESE ARE ALSO POSTED ON THE HOMEWORK PAGE WITH NOTES ABOUT WHAT I HAVE DONE. 1.) If a star has a temperature only 7/10 that of our Sun but a radius 10 times our Sun's, how would its luminosity compare to our Sun? 2.) If a star has a mass 11 times our Sun's mass, what would be its lifetime on the main sequence? What if the mass were 0.09 that of our Sun? 3.) If the parallax for a star is 0.015 arc sec (as measured by the Hipparchus satellite) how far away is it in parsec? In Light Years? If it has an absolute magnitude of 3, how bright would it appear from Earth? 4.) If the temperature of a star is 7800 K, where is the peak wavelength from Wien's Law? Assuming that it is a Main Sequence star, what spectral class and absolute magnitude would it have? 5.) If a star has an Absolute Magnitude 50 times brighter than our Sun, what would it be? If it appears as a 5 magnitude star, how far away is it?