ИСТИНА

We carry out multicolor UBVRI CCD -- photometry of fast He/N nova KT Eri at the period from the end of 2009 till 2017 yrs. Also we added the BVRI observations from AAVSO. We were successful in catching the decline of the outburst. The amplitude of the outburst was 9 mag, which is more common for recurrent novae, then for the most powerful outbursts of classical novae with an usual amplitude of 10-19 mag, and no previous outbursts was found. Different authors found different values of period in quiescence (737, 376, 752, 203, 472 days), which can be devoted to the orbital rotation of the system. Because of this reason, we decided to obtain new time series observations to find the real value of orbital period. Also we have studied the colour indices variations during the decline and quiescence stages. Our observations and the observations of the other authors show that the periodicity can be devoted to the orbital rotation of the system, and supposed, that the donor star appears to be a RGB star. As a result, we calculated the main physical and geometric parameters of KT Eri, based on the new value of orbital period.