Period Variation of the Close Eclipsing Binary V405 Draconis

Abstract

Abstract We found a period variation of the close binary of EW type V405 Draconis. From the O − C diagram built using survey data, data from the literature, and our observations, we calculated a period increase rate (1/P)(dP/dt) of 2.72(0.03) · 10−6 yr−1. Along with the monotonic period increase, TESS data demonstrates a sign of a cyclic variation of the period. We estimated the period of such cyclic variations as 537.9(1.4) days with a semi-amplitude of 0.00200(0.00001) days. This can provide evidence for the presence of the third body in the system.