Search for global oscillations on Jupiter with a double-cell Magneto-Optical Filter

Doppler observations on Jupiter are presented and discussed. A two-cells Magneto-Optical Filter (MOF), able to obtain two separate signals, Red and Blue, on the opposite wings of the Sodium D-lines, along with a continuum reference signal, has been used. This set of data permits to discriminate between real oscillations and albedo \modes" by means of the two algorithms D = (B - R)=(B + R) and S = (B + R)/continuum. No unambiguous oscillation modes were detected with amplitudes above the 1- level of 1.2 m s-1 in the range between 0.5 and 0.7 mHz. However, using rened analysis for signal recovery in a noisy background we notice an increase of power also in the region of the solar 5 min oscillations. The albedo variations on the Jupiter's surface and instrumental eects are addressed to be responsible for the spurious signals.