We present new photometric observations of TX CVn, CH Cyg, AX Per and AR Pav. The main results can be summarized as follows: TX CVn: The historical 1893-2000 photographic/B-band light curve (LC) is presented for the first time. From 1892 to ~1920, the star was quiet, but then entered a series of outbursts peaking in 1920, 1945, 1952 and 1962. From ~1988 till the present time, TX Cvn has gradually declined. CH Cyg: Our observations cover an active phase, which began in May 1998. At the beginning of June 1999 the star's brightness in the U band rapidly decreased due to an eclipse of the active inner binary (the symbiotic pair) by a cool giant in the outer orbit. AX Per: The historical 1887-2000 photographic/B-band LC is summarized here for the first time. It is characterized by long-lasting periods of quiescence with the superposition of a few bright stages lasting about 1.5 orbital cycles. Our photoelectric U,B,V observations revealed a drastic change in the LC profile, which occurred after JD 2 450 000 (1995.8). A small 0.6 mag flare at that time and consequently very broad wave-like variation in the LC developed. This event was caused by the dilution of a shell around the hot star. AR Pav: Our observations show that the recent active phase, which began in 1985.7 is over. During the activity, AR Pav developed a complex wave-like variation at the level of ~1.5 mag in the visual band. The transition to a quiet phase was rapid -- the wave-like variation disappeared.
Contributions of the Astronomical Observatory Skalnate Pleso
- Pub Date:
- April 2000