==> This proposal requests an upgrade from Priority 3 for KVOLK.LOWTEMPL
The IRAS Low Resolution Spectrometer detected a small number of sources with
featureless spectra of very low colour temperature (about 200 K) which are not
HII region sources.  The spectra closely resemble those of asteroids but the
objects are stellar and their CO line emission properties are typical of mass
losing AGB stars.  The broad band IRAS colours of these objects are similar to
those of planetary nebulae so they may be PNs or objects evolving to the PN
phase.  The circumstellar dust shells of these objects seem to be unusual.
In the previous round of ISO competition, this proposal was awarded priority
2 and priority 3 time.  Here we request an upgrade of priority 3 observations
with the particular goal of obtaining LWS01 observations of two of the
brighter of these objects.  The LWS observations will provide additional
spectral coverage not possible from the ground, which will allow for the
detection of spectral features for identification of the nature of the dust.