Observations of Doppler oscillations in a solar prominence

We report on the observation of Doppler oscillations in a quiescent limb prominence. Fourier analysis of the data reveals an oscillatory period of 7.5 min, whose phase varies linearly at 16 consecutive points (7280 km) along the slit. This yields an upper limit for the perturbation wavelength of 20000 km. Wavelet analysis confirms the above period and indicates an oscillation lifetime of 12 min. Moreover, the disturbance appears to travel at a speed greater than 4.4 km s^-1. A comparison of these results with the predictions of some theoretical models is made.