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trum like that of our sun, and appear yel-
lowish to the eye.
ˆ
ˆ
The third class includes I l Herculis, I l
Orionis (Betelgeux), Mira Ceti, and about
500 red and variable stars. The spectrum
has fluted bands shaded from blue to red,
and sharply defined at the more refrangible
edge.
The fourth class is a small one, contain-
648
