Question

The stars, Rigel and Betelgeuse, are both found in the constellation, Orion. Rigel is a blue supergiant, and Betelgeuse is a red supergiant. Which of the following correctly compares the temperatures of Rigel and Betelgeuse?
a
Rigel is hotter than Betelgeuse, because blue stars are hotter than red stars.
b
Betelgeuse is hotter than Rigel, because red stars are hotter than blue stars.
c
Rigel and Betelgeuse are close to the same temperature, because they are both super giants.
d
Betelgeuse and Rigel are close to the same temperature, because they are about the same distance from the Sun.

Answer 1

Answer: a

Explanation: The color of a star is linked to its surface temperature. The hotter the star, the shorter the wavelength of light it will emit. The hottest ones are blue or blue-white, which are shorter wavelengths of light. Cooler ones are red or red-brown, which are longer wavelengths.