Symbiotic stars on Asiago archive plates

The rich plate archive of the Asiago observatory has been searched for plates containing the symbiotic stars AS 323, Ap 3-1, CM Aql, V1413 Aql (= AS 338), V443 Her, V627 Cas (= AS 501) and V919 Sgr. The program objects were found on 602 plates, where their brightness has been estimated against the UBV(RI)_C photometric sequences calibrated by Henden & Munari (2000). AS 323 is probably eclipsing, with a preliminary P=197.6 day period. If confirmed, it would be the shortest orbital period known among symbiotic stars. CM Aql does not seem to undergo a series of outbursts, its lightcurve being instead modulated by a large amplitude sinusoidal variation with a P ~ 1058 day period. V627 Cas presents a secular trend, in agreement with the possible post-AGB nature of its cool component. Table~1 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/370/503