OBSERVATIONS OF THE DUST AROUND EVOLVED STARS

ISOPHOT has been used to obtain low resolution spectra from 2.5 mu m t o 5 mu m and 5.8 mu m to 11.6 mu m and multi-aperture photometry at 60 mu m of several evolved stars; oxygen-rich and carbon-rich (including the peculiar carbon-rich stars R CrB and RY Sgr). R CrB was observed early in the ISO mission, 3 weeks after it had been at minimum light. Another spectrum was obtained several months later. The second spectru m shows that the broad plateau (from around 6 mu m to 8 mu m) is still present but the flux density has declined from 60Jy to 50Jy. The spec trum for RY Sgr shows the same type of plateau. The multi-aperture dat a suggest that the dust shells are resolved around R CrB, RY Sgr, Y CV n and RS Lib.