Object Analysis

Mira (Omicron Ceti) is a red giant star estimated to be 200–400 light-years from the Sun in the constellation Cetus. It is the prototype of Mira variables. Mira is a binary star system, consisting of a variable red giant (Mira A) and a white dwarf companion (Mira B).

Mira A is a pulsating variable star that changes its brightness by a factor of 1,000 over a period of roughly 332 days. At its brightest, it is easily visible to the naked eye; at its faintest, it requires a telescope. It is in the final stages of its life, shedding its outer layers into space.

NASA's GALEX telescope discovered that Mira is leaving a comet-like tail of shed material 13 light-years long in its wake as it plows through the interstellar medium at 130 km/s. This tail contains enough material to form 3,000 Earths.