HAT-P-36 T80, T100 light curves and O-C

We found an increase in the orbital period of HAT-P-36 b at a rate of 0.014 seconds per year from the best fitting quadratic function, which is only found in the TTV constructed by making use of the mid-transit times measured from detrended light curves, against an expectation of an orbital decay based on its parameters. We refined the values of these system parameters by modelling the Spectral Energy Distribution of the host star, its archival radial velocity observations from multiple instruments, and most precise transit light curves from the space and the ground covering a wide range of wavelengths with EXOFASTv2 (Eastman, 2017, ascl, 1710, 003).

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 days, which might have been caused by instrumental systematics but should be tracked in the future observations of the target.