Magnetic Activity and Orbital Period Study for the Short-period RS CVn–type Eclipsing Binary DV Psc

摘要

Using 27 sets of new multiband photometry light curves acquired from our long-term photometric campaign carried out in the last 5 yr and high-resolution spectroscopic data from seven nights, we analyzed the physical mechanisms of period variation, starspot cycle, optical flares, and chromospheric activities of the eclipsing binary DV Psc. Our updated O???C diagram covering a period of approximately 20 yr shows an oscillation in its orbital period. This variations might be caused by a third body with an orbital period of 14.58?±?0.28 yr. There are two active regions of starspots at longitude belts of about 90° and 270°. We obtained its starspot cycles with periods of 3.60?±?0.03 yr and 3.42?±?0.02 yr at about 90° and 270°, respectively. Moreover, the magnitude difference of Max.?I–Max.?II shows cyclic oscillation of 5.15?±?0.01 yr. During our decade long photometric campaign, we observed DV Psc a total of 326.4 hr, detected 18 outbursts (12 of them have never been reported) with flare energies in the range of (6.62–1106.85)?×?1024 J. The slope of the relationship between the phase of the max flare and spots is 0.842?±?0.083, implying a correlation between spots and flares. We discovered evidence for a correlation between the rotation period and the activity cycle for the short-period eclipsing binaries. Our high-resolution spectroscopic observations of DV Psc show obvious emissions above continuum in the H α line and small self-reversal emissions of the Ca ii IRT lines.