http://arxiv.org/abs/2111.06551
Star-planet tidal interaction can explain the orbital migration of hot Jupiters, supported by the observed transit timing variation (TTV). We report the TTV of XO-3b, using TESS modeled timings and archival timings. We generate a photometric pipeline to produce light curves from raw TESS images and find the difference between our pipeline and TESS PDC is negligible for timing analysis. TESS timing presents a shift of 17.6 minutes (80 $\sigma$), earlier than the prediction from the previous ephemeris. The best linear fit for all timings available gives a Bayesian Information Criterion (BIC) value of 439. A quadratic function is a better model with a BIC of 56. The previous ephemerises are all under the assumption of a constant period and have BICs larger than the best linear fit when fitting transit timings. The period derivative obtained from a quadratic function is -6.2$\times$10$^{-9}$$\pm$2.9$\times$10$^{-10}$ per orbit, indicating an orbital decay timescale 1.4 Myr. We find that the orbital period decay can be well explained by tidal interaction. The `modified tidal quality factor’ $Q_{p}’$ would be 1.8$\times$10$^{4}$$\pm$8$\times$10$^{2}$ if we assume the decay is due to the tide in the planet; whereas $Q_{*}’$ would be 1.5$\times$10$^{5}$$\pm$6$\times$10$^{3}$ if tidal dissipation is predominantly in the star. The precession model and the R$\o$mer effect model seem to be ruled out due to the non-detection of transit duration variation and stellar companion. We note that the follow-up observations of transit timing and radial velocity monitoring are needed for fully discriminating the different models.
F. Yang and X. Wei
Mon, 15 Nov 21
30/52
Comments: 7 pages, 4 figures, submitted