2M1938+4603: a rich, multimode pulsating sdB star with an eclipsing dM companion observed with Kepler

摘要: 2M1938+4603 (KIC 9472174) displays a spectacular light curve dominated by strong reflection effect and rather shallow, grazing eclipses. The orbital period is 0.126 d, the second longest yet found for an eclipsing sdB+dM, but still close to minimum 0.1-d among such systems. phase-folded Kepler was used detrend effects from data set. amplitude spectrum of residual reveals rich collection pulsation peaks spanning frequencies similar 50 4500 mu Hz. presence complex in both p- g-mode regions has never before been reported compact pulsator. Eclipsing sdB+dM stars are very rare, with only seven systems known one pulsating primary. Pulsating binaries especially important since they permit masses derived seismological model fits be cross-checked mass constraints. We present first analysis this star based on 9.7-d commissioning extensive ground-based photometry spectroscopy that allow us set useful bounds system parameters. derive radial-velocity K-1 = 65.7 +/- 0.6 km s(-1), inclination angle i 69 degrees.45 0 degrees.20, find components M-1 0.48 0.03 M-circle dot M-2 0.12 0.01