Whole Earth Telescope Observations of PG 0014+067, a Key Pulsating Subdwarf B Star

摘要

PG 0014+067 is one of the most promising pulsating subdwarf B ( sdB) stars for seismic analysis as it is a 'typical' pulsating sdB star with a rich pulsation spectrum. The richness of its pulsations, however, poses a fundamental challenge to understanding the pulsations of these stars. The mode density is too rich to be explained only with radial and nonradial low degree l (l < 3) pmodes without rotational splittings. One proposed solution requires invoking modes with high degree (l = 3). An alternative interpretation explains this rich mode density via rapid internal rotation. With these models, this rich pulsation spectrum results from the presence of a few triplet (l = 1), quintuplet (l = 2) and radial (l = 0) p-modes. To critically examine competing theoretical models for these stars we need better frequency resolution and denser longitude coverage. Therefore, we observed this star with the Whole Earth Telescope network from eighteen sites for two weeks in October 2004. We find that PG 0014+067 does not fit any theoretical model currently available.