Asteroseismic Analysis of RY Leporis: The Post-main Sequence HADS in a Binary System

We present a comprehensive study of the pulsating primary component of the long-period binary system RY Lep. The spectral energy distribution and the absence of detectable lines indicate that the companion is likely a white dwarf. Atmospheric parameters and chemical abundances were determined from a high-resolution spectrum obtained with the Southern African Large Telescope. The spectroscopic analysis reveals an underabundance of iron-group elements and an enhancement of neutron-capture elements, including barium and europium, with an overall metallicity of [m/H]≈ −0.4. In the next step, we performed the first Fourier analysis of long-term photometric data from ASAS, SuperWASP, and TESS. In the TESS observations, we identify several additional frequencies not present in the ground-based data. The dominant frequency at 4.4415 day ^−1 is identified as a radial mode, most likely the first radial overtone. Finally, seismic modeling of RY Lep was carried out by fitting the dominant mode together with the secondary frequency at 6.5991 day ^−1 , considering two possible identifications for the latter: the third radial overtone or a dipole mode. Bayesian inference based on Monte Carlo simulations yields a stellar mass of ∼2.0 M _⊙ and an age of ∼730 Myr. All viable seismic models place RY Lep in the hydrogen shell-burning evolutionary phase, with a metallicity consistent with the spectroscopic determination.