Mira, a reddish variable star of Cetus, the Whale, a constellation on the celestial equator. (A variable star is one that changes in brightness.) The star's name means wonderful. When dimmest, Mira is an 8th- to 10th-magnitude star with an estimated temperature of 3,400 F. (1,871 C). Then it gradually increases in brightness for about 330 days to about third magnitude, and has a temperature of approximately 4,700 F. (2,593 C).

Mira is some 400 times larger than the sun and can be seen with the unaided eye for 150 days each year. Mira was the first variable star discovered. It was discovered by David Fabricius, a German astronomer, in 1596.