EDP Sciences
Free access
Volume 372, Number 1, June II 2001
Page(s) 317 - 325
Section The solar system
DOI http://dx.doi.org/10.1051/0004-6361:20010455

A&A 372, 317-325 (2001)
DOI: 10.1051/0004-6361:20010455

Search for global oscillations on Jupiter with a double-cell sodium magneto-optical filter

A. Cacciani1, M. Dolci1, 2, P. F. Moretti1, 3, F. D'Alessio4, C. Giuliani2, E. Micolucci2 and A. Di Cianno2

1  Università degli Studi di Roma "La Sapienza", P.le A. Moro 5, 00185 Rome, Italy
2  Osservatorio Astronomico "V. Cerulli" di Teramo, Via M. Maggini, 64100 Teramo, Italy
3  Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli, Italy
4  Osservatorio Astronomico di Roma, Via Frascati 33, 00040, Monte Porzio Catone, Italy

(Received 30 January 2001 / Accepted 22 March 2001 )

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 ${\cal D}=(B-R)/(B+R)$ and ${\cal S}=(B+R)$/conti nuum. No unambiguous oscillation modes were detected with amplitudes above the 1-$\sigma$ level of ~1.2 m s-1 in the range between 0.5 and 0.7 mHz. However, using refined 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 effects are addressed to be responsible for the spurious signals.

Key words: planets and satellites: general

Offprint request: M. Dolci, dolci@astrte.te.astro.it

© ESO 2001