Fourth meeting on hot B subdwarfs and related objects
du 20 au 24 juillet 2009
[en] The hot pulsating sdB star PG 1605+072 exhibits uncommon spectroscopic and pulsation prop- erties, and is one of the biggest challenge in the field of sdB star modeling. Two hypotheses have been proposed to explain its unusually rich pulsation spectrum. The first is the natural explanation of a fast-rotating pulsator, which lifts the (2l+1)-fold degeneracy of the frequency components. Another approach, where PG 1605+072 can be seen as a slow rotator, considers that the numerous low amplitude frequency components are second- and third-order harmonics and nonlinear com- binations of the highest amplitude frequencies. We investigated the two hypotheses in the light of asteroseismology, using our latest tools - including pulsation codes that incorporate star rotation and new generation complete sdB models. The results of both approaches are presented, showing interesting results and raising new questions for our understanding of this mysterious sdB star.