Detection of Jovian seismic waves: a new probe of its interior structure

¹ Institut d’Astrophysique Spatiale (UMR 8617), Faculté des Sciences d’Orsay, Université Paris Sud, Bâtiment 121, 91405 Orsay Cedex, France
e-mail: Patrick.Gaulme@ias.u-psud.fr
² Laboratoire Fizeau, Université de Nice, CNRS-Observatoire de la Côte d’Azur, 06108 Nice Cedex 2, France
³ Laboratoire Cassiopée, Université de Nice, CNRS-Observatoire de la Côte d’Azur, 06108 Nice Cedex 2, France

Received: 16 March 2011
Accepted: 6 June 2011

Abstract

Knowledge of Jupiter’s deep interior would provide unique constraints on the formation of the Solar System. Measurement of its core mass and global composition would shed light on whether the planet formed by accretion or by direct gravitational collapse. At present, the inner structure of Jupiter is poorly constrained and seismology, which consists of identifying acoustic eigenmodes, offers a way to directly measure its deep sound speed profile, and thus its physical properties. Seismology of Jupiter has been considered since the mid 1970s, but hitherto the various attempts to detect global modes have led, at best, to ambiguous results. We report the detection of global modes of Jupiter, based on radial velocity measurements performed with the SYMPA Fourier spectro-imager. The global seismic parameters that we measure include the frequency of maximum amplitude 1213 ± 50 μHz, the mean large frequency spacing between radial harmonics 155.3 ± 2.2 μHz, and the mode maximum amplitude  cm s^-1, all values that are consistent with current models of Jupiter. This result opens the way to the investigation of the inner structure of the Solar System’s giant planets based on seismology techniques.