What is the luminosity of the Sun? What is the luminosity of a O type star? And what the luminosity of the K type star? Two stars have magnitudes of 4 and 9 respectively. How much brighter is the star with magnitude 4 than the star with magnitude 9? If these two star were the same absolute magnitude (-4), how much further is the star with apparent magnitude of 9 than the star with the apparent magnitude of 4? Describe the different layers of the Sun via their respective temperatures and pressures.
