Star Temperatures and Colors: Reflecting on Rigel and Betelgeuse

What do the colors of stars like Rigel and Betelgeuse indicate?

a) Different sizes

b) Different ages

c) Different temperatures

d) Different compositions

Answer:

c) Different temperatures

When looking at stars like Rigel and Betelgeuse, their colors actually indicate the temperatures of these celestial bodies. Rigel, appearing as a bright bluish star, is a blue star which indicates a higher surface temperature. On the other hand, Betelgeuse appears as a bright reddish star, signifying a relatively cooler surface temperature compared to Rigel.

The colors of stars are closely related to their temperatures due to the different wavelengths at which they radiate most intensely. Rigel's blue color suggests that it radiates most intensely in the ultraviolet part of the spectrum, indicating a higher surface temperature. Conversely, Betelgeuse's red color signifies that it radiates most intensely at longer wavelengths in the red part of the spectrum, pointing towards a cooler surface temperature.

Furthermore, the colors and temperatures of stars like Rigel and Betelgeuse also reflect stages in their life cycles. Rigel is larger and younger than Betelgeuse, with Betelgeuse nearing the end of its life cycle and expanding into a red supergiant. These differences in size, color, and temperature provide valuable insights into the evolutionary stages of stars.