Asteroseismology of sdB stars with FUSE

Abstract

The hot subdwarf B (sdB) stars form an homogeneous group populating an extension of the horizontal branch (HB) in the ($T_{\rm eff}$--$\log g$) diagram towards temperatures up to 40,000 K. The recent discovery that many of them are multimode pulsators has triggered a large observational and theoretical effort. We discuss the possibility of performing space-based asteroseismology with {\em FUSE}, and we demonstrate that periodic luminosity variations are already detectable in archival TTAG data of sdB stars. In particular, we report on the {\em FUSE} observation of the pulsator PF 1219+534, which shows the presence of periodic variations at 6.9 mHz and 7.8 mHz, consistent with those reported from ground--based observations.