The Sun's spectrum peaks in the green region (i.e., green is the most intense color in its spectrum). The spectrum of Rigel (the knee of Orion) peaks in the short-wavelength end of the visible spectrum. Compared with the Sun, Rigel is
A) cooler and redder.
B) hotter and redder.
C) cooler and bluer.
D) hotter and bluer.

Question

Quizplus · Accepted Answer

Rigel's spectrum peaking in the short-wavelength end of the visible spectrum (which includes blue and violet colors) indicates that it is hotter than the Sun, whose spectrum peaks in the green region. Hotter stars emit more light at shorter wavelengths, making them appear bluer.

The Sun's Spectrum Peaks in the Green Region (I