DISTRIBUTION OF DUST ABOUT OMICRON CETI AND ALPHA ORIONIS BASED ON 11 MICRON SPATIAL INTERFEROMETRY

Visibilities of omicron Ceti and alpha-Orionis have been measured at a wavelength of 11 mu-m by a two-element heterodyne interferometer with maximum baseline spacings of 4 and 13 m. The measurements show that dust extends to within approximately 3 stellar radii of the oxygen-rich star omicron Ceti, the temperature there being near 1200 K. While the majority of dust near alpha-Orionis is in a shell of inner radius 0".90, where the temperature is about 300 K, a region very near the star producing 11 mu-m radiation appears to be present. This may be represented as a stellar envelope of diameter 0".063 which is not transparent at 11 mu-m wavelengths.