2009PASP..121..699Y

light curves of V343 Orionis were observed with the 85 cm telescope at Xinglong Station of the National Astronomical Observatories of the Chinese Academy of Sciences, in 2007 and 2008. Using the Wilson-Devinney program, the photometric solution of V343 Ori was first deduced from those observations. Photometric results indicated that V343 Ori is an A-subtype W Ursae Majoris binary, whose mass ratio and overcontact degree are and, respectively. The asymmetric light curves (i.e., O'Connell effect) were modeled by the spot model. The spot area is up to 1.21% of the area of the more massive component. All light minimum times for V343 Ori, spanning over 80 yr, were used in analyzing the orbital period change. From the curve, there exists a long-term orbital period increase at a rate of, which may be caused by the mass transfer from the less massive component to the more massive one. With mass transfer, the orbital angular momentum decreases while the spin angular momentum increases. When, this kind of binary (e.g., V343 Ori), with high overcontact degree and period increase, may evolve into a rapid-rotating single star.