Noun
Mira variable (plural Mira variables)
(astronomy) Any of a class of pulsating variable stars characterized by very red colours, pulsation periods longer than 100 days, and amplitudes greater than one magnitude in infrared and 2.5 magnitude at visual wavelengths.
It is a Mira variable with a minimum magnitude of 10 and normal maximum magnitude of 6; it periodically brightens to magnitude 4.4. Source: Internet
It is divisible in binoculars.sfn R Equulei is a Mira variable that ranges between magnitudes 8.0 and 15.7 over nearly 261 days. Source: Internet