The Brightness Distribution of IRC + 10216 at 11 Microns *

The brightness distribution of IRC +10216 at a wavelength of 11 microns has been measured in detail using a spatial interferometer. This brightness distribution appears to have azimuthal symmetry; an upper limit of 1.1 may be set to the ellipticity at 11 microns if the object has a major axis oriented either along or perpendicular to the major axis of the optical image. The radial distribution shows both compact and extended emission. The extended component, which is due to thermal emission.from circumstellar dust, contributes s<* 91% of the total flux and has a 1/e diameter of 0.90". The 2 tapered shape of this component is consistent with a 1/r dust density dependence. The compact component is unresolved /\ (less than 0.2" in diameter) and represents emission from the central star seen through the circumstellar envelope. *This work is supported in part by NASA Grant NGL 05-003-272 and NSP Grant AST77-12256. c_ IHASA-CR-157646P THE "BRIGHTNESi N79-16750 DISTRIBUTION OF IBC +10216 AT 11 MICEONS {California Oniv.) 15 p HC A02/MF A01 CSCI 03A Onclas G3/89 43589 https://ntrs.nasa.gov/search.jsp?R=19790008579 2017-09-12T18:48:11+00:00Z