Dr. Perry will use this grant to complete an observational study of the dust component of the interstellar medium in the neighborhood of the Sun. This study concentrates on stars accessible from the Southern Hemisphere. The results will complete the coverage of the spatial distribution of the interstellar reddening in the solar neighborhood, as similar data for stars in the Northern Hemisphere have already been analyzed. Although cosmic dust may comprise only one percent of the interstellar medium, its presence has a pronounced effect on astronomical observations because it is a wavelength dependent absorber of radiation from stars. It is essential, therefore, in many astronomical studies to correct for this reddening effect for any direction in space and at various distances from the Sun. Dr. Perry's aim is to provide reliable information on which astronomers can make a reddening correction.
