N-BAND OBSERVATIONS OF COMET AUSTIN 1989C1 - 1ST IMAGES WITH THE C10-MU CAMERA

We report here on the first observations obtained with the mid-infrare d camera C10mu, mounted on the Canada-France-Hawaii Telescope in May 9 0. The main originality of this camera relies on its LETI/LIR detector array, whose large well capacity (> 10(7) electrons) made easy broad- band imaging observations over the entire atmospheric window (8-13 mum ). As an illustration of the camera capabilities, we present high-angu lar resolution (0.7'' pxl-1) N-band images of comet Austin. At the tim e of the observations (1990 May 6.6 UT), the comet was located at 0.45 AU from the earth, so that we were able to measure the surface bright ness profile over a range of distances from the nucleus (300-3000 km) not yet well studied.