The bright star named Rigel has a luminosity of 66,000 L _$\wedge$ and a temperature of 11,000 K. What is its radius? Note that the temperature of the Sun is 5,800 K. A) 5 R _$\odot$ B) 30 R _$\odot$ C) 70 R _$\odot$ D) 135 R _$\odot$ E) 190 R _$\odot$

Question

Quizplus · Accepted Answer

Using the formula for luminosity $ L = 4\pi R^2 \sigma T^4 $, and comparing Rigel's luminosity and temperature to the Sun's, we find that Rigel's radius is approximately 70 times that of the Sun.

The Bright Star Named Rigel Has a Luminosity of 66,000 ∧\wedge∧

The Bright Star Named Rigel Has a Luminosity of 66,000 $\wedge$