2013/04/22 by E. Sipahi, Sipahi, E., C. Ibanoglu +7
Physics and Astronomy · #FOS: Physical sciences #Solar and Stellar Astrophysics (astro-ph.SR) #astro-ph.SR
paper · pdf · doi:10.48550/arxiv.1304.6056
25 pages, 9 Tables, 9 Figures, Accepted Revista Mexicana de Astronomía y Astrofísica. arXiv admin note: substantial text overlap with arXiv:1211.1200
arxiv created 2013/04/22 · arxiv updated 2013/04/23
BVR light curves and radial velocities for the double-lined eclipsing binary V1135 Her were obtained. The brighter component of V1135 Her is a Cepheid variable with a pulsation period of 4.22433±0.00026 days. The orbital period of the system is about 39.99782±0.00233 days, which is the shortest value among the known Type II Cepheid binaries. 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. Our analyses of the multi-colour light curves and radial velocities led to the determination of fundamental stellar properties of both components of the interesting system V1135 Her. The system consists of two evolved stars, G1+K3 between giants and supergiants, with masses of M1=1.461±0.054 \Msun ~and M2=0.504±0.040 \Msun and radii of R1=27.1±0.4 \Rsun and R2=10.4±0.2 \Rsun. 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=7500±450 pc using the BVR magnitudes and also the V-band extinction. Location in the Galaxy and the distance to the galactic plane with an amount of 1300 pc indicate that it probably belongs to the thick-disk population. Most of the observed and calculated parameters of the V1135 Her and its location on the color-magnitude and period-luminosity diagrams lead to a classification of an Anomalous Cepheid.