Abstract:
The IRAS observations of R Cr B, SU Tau and V 348 Sgr indicate the existence of a cool dust component of temperature about 30 K in R Cr B and SU Tau and less than or equal to 100 K in V 348 Sgr, in addition to the hot dust. It is suggested that this cool dust shell is a remnant of the stage when these stars were red giants for the first time. Although R Cr B was observed by IRAS during a visual light minimum no significant IR flux increase was apparent.
