Question

Question 61 2.5 pts Star B's luminosity is 26.8 times that of star A's luminosity. Star Ais 21.5 pc away, while star Bis 3.8 pc away. So, star B appears __times the brightness of star A. Report your answer to four significant figures, please.

Answer 1

Solution Luminosity of Star is given by = 4T d²b L- Luminosity in w b = Brightness in w/ m2 d = Distance in m given date for Star B given data for Star A LA- L Lg = 26.8 LA da = 21.5PC 1 PL = 3.1x106m dB = 3.8 PC da = 21.5X31X106m dB = 3.8 x 3.1x1016 Now Luminosity formula for A How Luminosity formula for B LA = 415 du bA . LB = 40 de be dividing equation 1 by equation & be = (215x3-1x10169? (510x3-1400/6,2 ( 26.6) bm (3.883.1 be = 857.9155 bA bo = 857.9155 bA be = $57.9 bA Brightness of Star B is 857. 9 times the boightness of Star A.