First results of ISO-SWS observations of Jupiter

Th. Encrenaz - Th. de Graauw - S. Schaeidt - E. Lellouch - H. Feuchtgruber - D. A. Beintema - B. Bézard - P. Drossart - M. Griffin - A. Heras - M. Kessler - K. Leech - A. Morris - P. R. Roelfsema - M. Roos-Serote - A. Salama - B. Vandenbussche - E. A. Valentijn - G. R. Davis - D. A. Naylor

Abstract:

The spectrum of Jupiter has been recorded between 2.75 and 14.5 microns with the grating mode of the Short-Wavelength Spectrometer (SWS) of ISO. The resolving power is 1500. The main preliminary results of this observation are (1) at 3 microns, the first spectroscopic signature, probably associated with NH₃ ice, of the Jovian cloud at 0.5 bar and (2) the first detection of a thermal emission at the center of the CH_4-v3 band at 3.3 microns, showing evidence for a high temperature in the upper jovian stratosphere (T=800 K at P=0.16 microbar). In addition, the R(2) HD line has been detected for the first time in Jupiter, using the Fabry-Pérot (FP) mode of the SWS, with a resolving power of 31000. A preliminary analysis of the HD line indicates a D/H ratio of about 2.2 10^-5.

Keywords:
Planets - Jupiter - infrared:solar system

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