* Astronomy

Title: TYC 1031 1262 1: An Anomalous Cepheid in a double-lined eclipsing binary
Authors: E. Sipahi, C. Ibanoglu, O. Cakirli, S. Evren

Multi-colour light curves and radial velocities for TYC 1031 1262 1 have been obtained and analysed. TYC 1031 1262 1 includes a Cepheid with a period of 4.15270 ±0.00061 days. The orbital period of the system is about 51.2857 ±0.0174 days. The pulsation period indicates a secular period increase with an amount of 2.46 ±0.54 min/yr. The observed B, V, and R magnitudes were cleaned for the intrinsic variations of the primary star. The remaining light curves, consisting of eclipses and proximity effects, are obtained and analysed for orbital parameters. The system consists of two evolved stars, F8II+G6II, with masses of M_1=1.640 ±0.151 solar masses and M_2=0.934 ±0.109 solar masses and radii of R_1=26.9 ±0.9 solar radii and R_2=15.0 ±0.7 solar radii. The pulsating star is almost filling its corresponding Roche lobe which indicates the possibility of mass loss or transfer having taken place. We find an average distance of d=5070 ±250 pc using the BVR and JHK magnitudes and also the V-band extinction. Kinematic properties and the distance to the galactic plane with an amount of 970 pc indicate that it belongs to the thick-disk population. Most of the observed and calculated parameters of the TYC 1031 1262 1 lead to a classification of an Anomalous Cepheid.

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