  The Fourier spectral analysis of this object suggests a nonlinear pulsation
of period approximately 14d with a 3:2 frequency lock between two vibrational
modes. We discuss an extensive search that we have performed in the L, M, Teff
space for models of period 14 - 16 days that exhibit this particular resonance.
We find models satisfying the resonance constraints both in the Cepheid and in
the post AGB regimes. The nonlinear pulsations of several candidates are
presented. The nature of the star remains a mystery as none of the models
satisfies all the observational constraints.
