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    Öğe
    First TESS light curve solution and orbital period analysis of V567 And
    (Elsevier, 2022) Ozturk, Oguz
    The photometric light curve of V567 And observed by the Transiting Exoplanet Survey Satellite (TESS) was solved for the first time in this study. According to the final model parameters, it was concluded that the system is a semi-detached eclipsing binary star system. The mass and radius values of the primary and secondary components were estimated as M-1 = 1.83 +/- 0.18 M-circle dot and R-1 = 3.16 +/- 0.21 R-circle dot, and M-2 = 0.22 +/- 0.07 M-circle dot and R-2 = 2.63 +/- 0.43 R-circle dot, respectively. Orbital period variation of the system was also investigated for the first time in this study using one minima time given in the literature and 31 minima times calculated in this study. The downward parabolic variation of the O-C change of the system suggests a secular period decrease with a rate of 0.276 +/- 0.031 s/year. The O-C variation was interpreted in terms of the non-conservative mass transfer mechanism. The distance of V567 And was calculated to be 1229 +/- 61 pc from the distance modulus formula by taking into account interstellar extinction, which is in a good agreement with the distance value derived from the Gaia EDR3 parallax within error limits.
  • [ X ]
    Öğe
    New photometric analysis of five exoplanets: CoRoT-2b, HAT-P-12b, TrES-2b, WASP-12b, and WASP-52b
    (Oxford Univ Press, 2019) Ozturk, Oguz; Erdem, Ahmet
    We report 12, 11, 9, 10, and 8 new transit light curves of CoRoT-2b, HAT-P-12b, TrES-2b, WASP-12b, and WASP-52b, respectively, obtained at Canakkale Onsekiz Mart University Observatory and TUBITAK National Observatory in 2016 and 2017. These transit light curves were analysed using JKTEBOP code. Planetary radii of CoRoT-2b, HAT-P-12b, TrES-2b, WASP-12b, and WASP-52b were found to be 1.41 +/- 0.06 R-J, 0.95 +/- 0.04 R-J, 1.23 +/- 0.07 R-J, 1.82 +/- 0.14 R-J, and 1.22 +/- 0.06 R-J, respectively. The transit ephemerides of these five exoplanets were updated and transit-timing variation analyses were also performed, using the maximum likelihood method (MLM). Most of the Lomb-Scargle (LS) periodograms of the timing residuals do not give any peak above false alarm probability levels. However, LS periodograms of CoRoT-2b show several significant peaks, and they are probably due to the magnetic activity of the host star and additional bodies in the system. On the other hand, the O-C diagram of WASP-12b displays a downward parabolic variation and indicates that the orbital period of the exoplanet is secularly decreasing. The mechanism responsible for this period decrease is discussed in terms of the orbital decay model. The tidal quality parameter Q(star)' of the host star WASP-12 was found to be (1.75 +/- 0.16) x10(5), which is close to theoretical predictions for sun-like stars. Classification of the five exoplanets based on their equilibrium temperatures and Safronov numbers was re-examined, comparing the sensitive data of 211 well-known exoplanets from the Exoplanet Data Explorer data base with ours.