Photometry of symbiotic stars VIII. EG And, TX CVn, BF Cyg, CH Cyg, AG DRA and AX Per

We present photoelectric U,B,V,R observations of 6 classical symbiotic stars. The main results can be summarized as follows: EG And (HD 4174, BD+39 167) : A sinusoidal variation displaying two maxima (minima) during the orbital period was observed also in the R band. TX CVn (HD 63173, BD+37 2318): A periodic, ~190-day, variation in the U band was found, corresponding to the orbital period of the binary. The shaping and colour indices of the minima suggest that they are probably caused by eclipses. BF Cyg (MWC 315, Hen 1747): A wave-like variation in the light curve (LC) indicates that the system has finally returned to quiescence. A minimum of the light was observed at JD 2 450 684.5. CH Cyg (HD 182917, BD+49 2999): This star persisted in a quiescent phase till May 1998. The last observations indicate a brightening of ~1.5 mag in U, showing that CH Cyg just entered a new active phase. AG Dra (SAO 16931, BD+67 922): Our measurements cover the recent eruption centred around JD 2 450 670 (1997.6) and the following minimum. AX Per (MWC 411, GCRV 896): The recent photometry revealed a deep minimum lasting about 400 days around JD 2 450 280 (1996.5). The timing of two other minima in the historical LC and colour indices during the recent minimum suggests that they can be caused by eclipses of the inner binary (the symbiotic pair, P_orb=680 days) by a giant star (R ~ 200-300 R_Sun) orbiting it in a long-period (46.5-yr) orbit.