Question

The table below list four stars that are readily visible from earth along with their apparent color as seen by the human eye. Using numbers, with 1 being the hottest and 4 being the coolest, rank the stars according to surface temperature. 4. Relative Temperature P-4A P-4B P-4C P-4D or As Seen From Earth Relative T Star Arcturus Rigel A Betelgeuse Our Sun Orange Blue-White Red Yellow

Answer 1

This problem can be solved by considering the wavelength of the color of stars seen by human eyes. The color Red has the longest wavelength followed by orange followed by yellow and blue-white. According to Wien's displancement law, wavelength of the radiator is inversely proportional to the temperature of the radiator. Hence the star with longest wavelength will be the coolest one and the one with shortest wavelength will be the hottest one.

Rigel A ......1

Our Sun..........2

Arcturus.........3

Betelgeuse.....4.