Akademik Veri Yönetim Sistemi
ACTA ASTRONOMICA, cilt.71, sa.3, ss.223-242, 2021 (SCI-Expanded)
We study the most precise light curves of the planet-host HAT-P-36 that we obtained from the ground primarily with a brand-new 80 cm telescope (T80) very recently installed at Ankara University Kreiken Observatory (AUKR), Turkey and also from the space with Transiting Exoplanet Survey Satellite (TESS). The main objective of the study is to analyze the Transit Timing Variations (TTV) observed in the hot-Jupiter type planet HAT-P-36 b, a strong candidate for orbital decay. Our analysis is based on our own observations as well as those acquired by professional and amateur observers since its discovery. HAT-P-36 displays out-of-transit variability as well as light curve anomalies during the transits of its planet due to stellar spots. We collected and detrended from these anomalies all complete transit light curves we had access to. We modeled transits with EXOFAST and measured the mid-transit times forming a homogeneous data set for a TTV analysis. We found an increase in the orbital period of HAT-P-36 b at a rate of 0.014 s per year from the best fitting quadratic function. This increase is only found in the TTV constructed from the mid-transit times measured from detrended light curves. We refined the values of the system parameters by modeling with EXOFASTV2 the Spectral Energy Distribution of the host star, its archival radial velocity observations from multiple instruments, and the most precise transit light curves from the space and ground covering a wide range of wavelengths. We also analyzed the out-of-transit variability from TESS observations to search for potential rotational modulations through a frequency analysis. We report a statistically significant periodicity in the TESS light curve at 4.22 +/- 0.02 d, which might have been caused by instrumental systematics but should be tracked in the future observations of the target.