The Effect Of Stellar Pulsation Cycles On Dust Formation: A Temporal Study Of Mid-infrared Spectrum Of O-rich AGB Star, T Cep

Abstract

Pulsation is believed to be the driving mechanism behind mass loss and dust formation around AGB stars. We present a temporal study of T Cep, a long-period Mira variable, which was observed seven times during a 16 month period spanning a single pulsation cycle. The observed spectral dust features change over the pulsation cycle of this Mira. In general, the overall apparent changes in spectral features can be attributed to changes in the dust temperature, resulting from the intrinsic pulsation cycle of the central star. However, not all feature changes are so easily explained. In particular, the classic interpretation of the broad complex features cannot be attributed to a simple mixture of alumina and glassy silicate. The peak features at 9.7, 10.8, 11.3, 13.1 μm are better explained by crystalline silicate or mixtures of crystalline silicate and alumina.