The most resonant pulsation frequency of δ Scuti stars

Abstract

AbstractPulsation of the Sun with a period of P0 ≈ 160 min discovered about two decades ago, is still waiting explanation. In view of the hypothesis about its cosmological origin, and attempting to find signature of this P0 periodicity among other (short‐period variable) stars, the pulsation frequencies of δ Sct stars are subjected to specific analysis. With a confidence level ≈ 3.8σ it is found that the frequency v0 = P0−1 ≈ 104 m̈Hz, within the error limits, appears indeed to be the most “resonant” one for the total sample of 318 pulsating stars of δ Sct type (the most commensurable, or “synchronizing”, period for all these stars occurs to be 162 ± 4 min). We conjecture that a) the P0 oscillation might be connected with periodic fluctuations of gravity field (metrics), and b) the primary excitation mechanism of pulsations of δ Sct stars, reffected by this “ubiquitous” P0 resonance, must be attributed perhaps to superfast rotation of their inner cores (their rates tend to be in near‐resonance with the “universal” v0 frequency). The arguments are given favouring a cosmoogical nature of the P0 oscillation.