Evolution of LMBs and Asteroseismology

We investigate pulsations of the red‐dwarf companion of the neutron star (NS) in a low‐mass binary (LMB). The illumination of the donor star by the pulsar’s high‐energy, non‐thermal radiation and relativistic wind may substantially affect its structure. We present a quantitative analysis of the oscillation spectrum of a red dwarf which evolved in an LMB and underwent a stage of evaporation. We calculate the p‐ and g‐modes for red dwarfs of masses within the interval 0.2–0.6 M⊙. For comparison, we present similar calculations for ZAMS stars of the same masses. In the case of less massive donor stars (∼0.2 M⊙) the oscillation spectrum becomes qualitatively different from that of their ZAMS counterparts. We also consider tidally forced g‐modes and perform a linear analysis of these oscillations for different degrees of the non‐synchronization between the orbital rotation and spin rotation of the red‐dwarf component. We discuss the triggering by these oscillations of the Roche‐lobe overflow and sudden mass lo...