THE PHOTOMETRIC BEHAVIOR OF A SYMBIOTIC STAR V919 SGR

We collected photometric observations of the symbiotic star V919 Sgr from the AAVSO and ASAS-SN databases, as well as UBVRI observations obtained at the Astronomical Institute of the Slovak Academy of Sciences. This symbiotic binary star belongs to the Z And type. Observers paid little attention to it until the latest outbursts that began in the 2000s The first observed outburst was described in 1991. In total, we found six outbursts of V919 Sgr. In particular, the star has recently shown significant activity, including a new active phase starting in 2022 and a rebrightening in 2023 that exceeded the previous year’s outburst by about 0.4 magnitudes (in V passband). To analyze the activity of V919 Sgr on short timescales, we used a "pattern scaling analysis" with a weighted "running parabola" (RP) approximation and additional "bi-square" weights. An optimal window half-width of 63 days minimized the rms statistical errors, and the B–V, V–R, and R–I color indices were determined. The B–V color index ranged from 0.53 at brightness maxima (10.15-10.76 in V) to 1.20 at magnitude 13.8. A periodogram analysis was also performed. However, due to the limited number of observations between outbursts, the period estimates are highly uncertain.