2019ApJ...877...75P

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) x 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.