Compact circumstellar dust envelopes of evolved AGB stars with heavy mass loss

Abstract

With the use of ISOPHOT on board ISO, we have carried out far-infrared mapping observations of the circumstellar dust envelopes around evolved AGB stars IRC—10529 and WX Psc which have an optically very thick circumstellar dust envelope. The radial sizes of their dust envelopes are very small indicating that the period of heavy mass loss which made the dense dust envelopes is not long. It is very likely that IRC—10529 and WX Psc have recently evolved into the final stage of AGB evolution with an extremely high mass loss rate.