Mira

Mira, variable star about 270 light-years away from the earth. The German astronomer Fabricius first observed the brightening and dimming of the star in 1596; later, variations in diameter and temperature were also noted. The diameter of Mira can be imagined as equal to that of the sun and all nearby planets, extending to a point somewhere beyond Mars. It is visible to the naked eye for about half the year; otherwise it can be seen through a telescope.

See also: Star.