Dr. Rabus, Markus

2022, Southworth, John, Barker, A. J., Hinse, T. C., Jongen, Y., Dominik, M., Jørgensen, U. G., Longa-Peña, P., Sajadian, S., Snodgrass, C., Tregloan-Reed, J., Bach-Møller, N., Bonavita, M., Bozza, V., Burgdorf, M. J., Jaimes, R. Figuera, Helling, Ch., Hitchcock, J. A., Hundertmark, M., Khalouei, E., Korhonen, H., Mancini, L., Peixinho, N., Rahvar, S., Dr. Rabus, Markus, Skottfelt, J., Spyratos, P.

HATS-18 b is a transiting planet with a large mass and a short orbital period, and is one of the best candidates for the detection of orbital decay induced by tidal effects. We present e xtensiv e photometry of HATS-18 from which we measure 27 times of mid-transit. Two further transit times were measured from data from the Transiting Exoplanet Survey Satellite ( TESS ) and three more taken from the literature. The transit timings were fitted with linear and quadratic ephemerides and an upper limit on orbital decay was determined. This corresponds to a lower limit on the modified stellar tidal quality factor of Q > 10 5 . 11 ±0 . 04 . This is at the cusp of constraining the presence of enhanced tidal dissipation due to internal gravity waves. We also refine the measured physical properties of the HATS-18 system, place upper limits on the masses of third bodies, and compare the relative performance of TESS and the 1.54 m Danish Telescope in measuring transit times for this system.