A tentative identification of Jovian global oscillations

Mosser, B.; Delache, Ph.; Schmider, F. X.; Gautier, D.
Bibliographical reference

Astronomy and Astrophysics (ISSN 0004-6361), vol. 251, no. 1, Nov. 1991, p. 356-364. Research supported by INSU and CNRS.

Advertised on:
Number of authors
IAC number of authors
Refereed citations
The identification of the Jovian frequency spectrum obtained by Schmider et al. (1990, 1991) is proposed from Doppler shift observations of the solar sodium D line reflected by the planet, as a signature of Jovian global-pressure modes. The spectrum, derived from 4 nights of observations, presents high-amplitude peaks whose origin in undoubtedly not noise, but it suffers from the daily interruption in the observations. Echelle diagram analysis has allowed the determination of a regular pattern, corresponding to the regularity indicated by the asymptotic theory (Tassoul 1980) revised for Jovian seismology (Provost et al., in preparation). The observed equidistance is not a direct measurement of the characteristic frequency, but is closely related to it. As expected two frequencies dominate the spectrum: the rotational frequencies of the earth and of Jupiter. However, it has been possible to construct an echelle diagram based on a frequency which satisfies three criteria. The physical implications of the low value of the characteristic frequency and of the large amplitudes of detected oscillations are discussed.