A Probable New BY Draconis Variable ZTF J021857.72+585950.1

We present our analysis of new photometric and spectroscopic data for a poorly studied star with an uncertain variability type (BY Dra or EW), ZTF J021857.72+585950.1. The observations were carried out with the 0.6-m and 2.5-m telescopes of the Caucasian Mountain Observatory and the 1.25-m telescope of the Crimean Astronomical Station of the Sternberg Astronomical Institute (Lomonosov Moscow State University) in 2019 2024. We found a period of 0.279 d and demonstrated that brightness variations resulted from rotation of a spotted chromospherically active star of the BY Dra type, which is consistent with the AAVSO classification. Based on our low-resolution spectra, we classified the star as K1V and found profile variations of the Halpha line both from night to night and during a single night. We also estimated the interstellar extinction A_V = 0.27 mag and distance to the star d = 154 pc.