It is now known that several main sequence stars possess
 circumstellar disks (Vega-like stars) which may be analogues
 of the protoplanetary disk of our own solar system. One of the
 best studied star is Beta Pic, whose disk has been optically imaged.
 While significant constraints were obtained on the general disk
 properties, little is known about the composition of the grains.
 We propose to use the SWS spectrograph to undertake high resolution
 spectroscopic observations of Beta-Pic and other Vega-like systems.
 The goal is to search for signatures of frozen CO and CO2, at
 respectively 4.67 and 4.27 mu, in order to put constraints on
 the composition of the circumstellar material. These observations
 will usefully complement the SWS and PHOT-S observations of the
 central program whose spectral resolutions are quite appropriate
 for searching for broad band signatures of polar
 molecules but too low for the narrow bands of CO and CO2.

 The interest in searching for CO and CO2 is that these molecules
 are expected to be important constituents of the
 circumstellar grains in Vega-like systems. Compositional inferences
 and detailed comparison with interstellar dust, circumstellar dust
 around younger stars, cometary ices and solar nebula models should
 lead to a better understanding of planetary system formation.