SIMBAD references

We present the analysis of time-resolved spectroscopy of the pulsating subdwarf B (sdB) star PG1605+072. From our main observing run of 16 nights we have detected velocity variations at five frequencies that correspond to those found in photometry. Based on these data, there appears to be change in amplitude of the dominant modes over about a year. However, when we include extra observations to improve the frequency resolution, we find that some of the frequencies are split into two or three. Simulations suggest that the apparent amplitude variation can be at least partially explained by a series of very closely spaced frequencies around the two strongest modes. By combining observations taken over ∼300d we conclude that some of the closely spaced modes are caused by one mode the amplitude of which is varying, however this frequency is still within ∼1µHz of an apparently stable frequency. Because of this kind of complexity and uncertainty we advise caution when trying to identify oscillation modes in this star.