PHOTOMETRY AND THE BLAZHKO EFFECT IN THE RR Lyr VARIABLE STAR Y Vul

The RR Lyr variable star Y Vul havebeen observed by using a CCD photometer during sev-eral seasons from 2011 to 2017. Nearly 5960 data pointswere obtained spanning over 53 nights. We found theamplitude and phase modulations with the amplitudesof 0.16 mag and 0.041 of the pulsating phase in V fil-ter; 0.15 mag and 0.041 of the pulsating phase in Rfilter, respectively. The frequency Fourier analysis ofthe light curves with the help of Period04 software wasperformed, Blazhko modulation period (59.20 days)and triplet structures in the Fourier spectrum were de-tected. The pulsation frequency components in theFourier spectrum were identified up to the 7th har-monic order, while the modulation side lobe frequen-cies – up to 9th order. The analysis of the light curvesmaxima resulted in the same value of the Blazhko pe-riod.Thefundamental pulsation period of the star hasbeen practically stable over a period of a hundredyears.