A PERIOD STUDY OF THE W URSAE MAJORIS-TYPE ECLIPSING BINARY GSC 03465-00810

摘要

GSC 03465-00810 is a cool, T_(eff) ≈ 4960 K, short-periodW UMa system with a photometric amplitude of o~m?3, and no obvious O'Connell effect. The O-C residuals of the times of minima clearly show that the system has a third body but the period is poorly constrained with P > 4000 d. The most likely period is P = 4111±46 d, and the corresponding light-travel-time semi-amplitude is O~d?0089, with e = 0.47 ± 0.04 and the close-binary period P_0 = 0.27668359(4) d. For P ≈ 4000 d the possible mass of the third body ranges from m_3 = 0.42 - 0.62 M_⊙ for the combined mass of the close binary m_(12) = 1.0 - 2.0 M_⊙， so there may be a significant third-light contribution. The upper limit of P is constrained only by perceived acceptable masses of the system. The eccentricity, a sin i, and the light-travel time of the third-body orbit all increase with increasing period. The peak magnitude of V = 14.62, distance of 900 pc, and almost zero reddening suggest that the system has M_v = 4-8, and may be o~m?5 more luminous than systems of similar period.