Mira (Omicron Ceti), Pulsating Variable Star. Mira is the brightest and most famous, long-period, pulsating variable in the sky. It gave the name to the whole category of variable stars known as Mira variables. It changes its brightness normally between magnitude 3 and magnitude 10. Mira is located 400 light years away in the Constellation of Cetus the Whale. This photograph was taken at RAS Observatory, Mayhill, NM on January 24, 2007 using a 10' F4 Takahashi Epsilon Scope and ST8 CCD camera for an 8 Minute exposure, LRGB.