VARIATION OF THE DUST COMPOSITION THROUGH THE TAURUS CLOUD INFRARED SPECTRA OF BACKGROUND STARS TOWARD THE TAURUS CLOUD

we propose to obtain infrared spectra with phots for about 30 stars located behind the taurus nearby dark cloud. for a handful of them which are bright enough, we would also like to obtain sws01 spectra. these observations will provide an essential tool to trace the evolution of the dust composition throughout the cloud and in particular when going from the dense cores to the much less dense regions. the spectral range of phots includes several signatures of ices such as h2o (3 micron), co2 (4.27 micron), co (4.67 micron), and silicates (9.7 micron). with sws01, the co2 (15.2 micron) and the 18 micron silicate bands can also be studied. these data will allow to understand under which conditions can the most reactive forms of ice survive at the surface of the rather stable silicate grains. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]