Mode identification in rapidly pulsating subdwarf B stars from monochromatic amplitude- and phase variations

We present a mid-term report on a project aimed at partially identifying the main modes of pulsation in the rapidly pulsating subdwarf B star PG 1047+003. Using the unique HIT-MS mode on FORS2 at the VLT we obtained ˜3000 spectra spread over 4 consecutive half-nights with a typical sampling rate of 20 s. These will be used to extract monochromatic pulsation amplitudes and phases that can be fit to model predictions in order to determine the degree ℓ of the mode in question.