The images were recorded in the 10 m atmospheric window at the Canada-France-Hawaii Telescope on December 8, 1992, between 3 UT and UT, and on December 9, 1992, between 45 UT ans 15 UT. We used "C10µ", a 6464 pixel camera which was developed by the Equipe Infrarouge of the Observatoire de Lyon, France (Vauglin et al. 1999). The spatial sampling is 0.7 arcsec per pixel. The size of Saturn was of about 16 arcsec on December 1992, the entire planet is then visible on the camera. This camera is sensitive in the 5 to 17 m range and we chose 6 wavelengths on a CVF (Circular Variable Filter) filter, having spectral resolution of 50. The first selected wavelength probes the thermal continuum, at 10.91 m. Owing to the low spectral resolution, this spectral interval is also slightly sensitive to the phosphine emission. The following wavelengths, 11.69 m and 12.47 m, are in the wings of the ethane band. The three last wavelengths, 13.09, 13.29 m and 13.48 m, correspond to the acetylene band emission. In order to calibrate the images, we also observed at all wavelengths the standard stars Peg and µCeph, whose infrared fluxes have been measured by IRAS (Infrared Astronomical Satellite, Olnon et al. 1986).
© European Southern Observatory (ESO) 2000
Online publication: March 28, 2000