RECENT RESULTS IN ASTRONOMICAL FOURIER-TRANSFORM SPECTROSCOPY

The characteristic of the Canada-France-Hawaii Fourier Transform Spect rometer, an astronomical high resolution FTS built in France, which is part of the permanent instrumentation of the telescope, are presented . This instrument is optimized to be able to work on faint sources in the presence of thermal background radiation, in the 1-5.4 mu m range. Very different types of objects are observed in order to probe their gas content, involving various astrophysical media: comets, planets an d their satellites, circumstellar envelopes and very young stars still embedded in their parent molecular cloud. Examples of results are giv en. Beside spectroscopy of individual objects, new modes of operation are explored. The use of the FTS as a seismometer to detect the pressu re oscillations of stars and giant planets has been tested. The field properties of the interferometer can also be exploited by combining th e FTS with modern infrared array detectors. Finally, the new challenge created by the future generation of very large telescopes is presente d.