Discovery of [CLC][ITAL]p[/ITAL][/CLC]-Mode Instabilities in the Hot Subdwarf B Star PG 1047+003

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Abstract
We report the discovery of multiperiodic luminosity variations in the hot B subdwarf PG 1047+003. At least five periodicities are seen in the light curve, from 104.2 s to 161.9 s, but others are also present at lower amplitudes in that interval. The largest oscillation has an amplitude of 9.2 millimag in white light and a period of 142.2 s. With atmospheric parameters Teff ~ 34,370 K and log g ~ 5.7 for PG 1047+003, these variations are identified with low-order radial and nonradial (p and f) pulsation modes. The similarity of periods and derived stellar parameters indicate that PG 1047+003 is a genuine member of the EC 14026 class, the latest and newest family of pulsators in the field of asteroseismology. However, it shows no evidence of a binary companion, implying that the mechanism for driving pulsations is internal to the star. We also report on the current status of our ongoing survey to search for additional sdB pulsators.
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