> If these stars are of normal A-star > like objects, then what would be the cause of 'fading' resembling those > of RCB stars? The light fading of these stars are distinguishing from those of the RCB: "fast" decline during days (hot star, V348 Sgr) or tens of days (cold stars) and then the slower recovering of normal light. i.e. a light curve has the very typical shape. An unvisibelity of star, as this was in the case of LO Cep, and CT Vul, etc, does not mean it is a star with the RCB variability. First condition is a full light curve. Alexander