PCS 181 Lecture Notes - Lecture 7: White Dwarf, Williamina Fleming, Binary Star
Document Summary
Last class: life and death of a star. Starts to die when h burns into he in the core. True brightness (energy emitted per second) of a star: luminosity. What we directly measure: apparent brightness, and apparent magnitude: higher magnitude stars are dimmer. Measure distance in parallax angle: distance in parsecs, big distance is small parallax, because they are so far away you won"t notice the difference (in shifts) Determine absolute magnitude: apparent magnitude star if it were at 10 pc, m= m + 5 5long (d) Using information we can get to determine the factors that make a star what it is. How much power (energy per second) the star emits light: directly related to the star"s distance from us, true measure of how much energy is put out. Related to absolute magnitude: (like celsius and fahrenheit) Actual equation (conversion: mstar msun = -2. 5log (lstar/lsun, lsun =3. 9 x1026 w, msun = 5. 14.
