Published online by Cambridge University Press: 12 April 2016
Symbiotic Miras are identified by their infrared characteristics. It is shown how an understanding of the evolutionary position of normal Mira variables together with the empirically established period luminosity relation can be used to derive various physical parameters for similar objects in symbiotic systems. The pulsation periods of symbiotic Miras measured so far fall between 280 and 580 days, their ages must be in the 5–10 Gyr range while main sequence masses of the order 1 to 1.5 M⊙ are indicated. The obscuration events seen in the IR light curves of several symbiotic Miras are highlighted as potentially important and possible causes are discussed.