WASP-4b Arrived Early for the TESS Mission

June 2019 • 2019AJ....157..217B

Authors • Bouma, L. G. • Winn, J. N. • Baxter, C. • Bhatti, W. • Dai, F. • Daylan, T. • Désert, J.-M. • Hill, M. L. • Kane, S. R. • Stassun, K. G. • Villasenor, J. • Ricker, G. R. • Vanderspek, R. • Latham, D. W. • Seager, S. • Jenkins, J. M. • Berta-Thompson, Z. • Colón, K. • Fausnaugh, M. • Glidden, Ana • Guerrero, N. • Rodriguez, J. E. • Twicken, J. D. • Wohler, B.

Abstract • The Transiting Exoplanet Survey Satellite (TESS) recently observed 18 transits of the hot Jupiter WASP-4b. The sequence of transits occurred 81.6 ± 11.7 s earlier than had been predicted, based on data stretching back to 2007. This is unlikely to be the result of a clock error, because TESS observations of other hot Jupiters (WASP-6b, 18b, and 46b) are compatible with a constant period, ruling out an 81.6 s offset at the 6.4σ level. The 1.3 day orbital period of WASP-4b appears to be decreasing at a rate of \dot{P}=-12.6+/- 1.2 ms per year. The apparent period change might be caused by tidal orbital decay or apsidal precession, although both interpretations have shortcomings. The gravitational influence of a third body is another possibility, though at present there is minimal evidence for such a body. Further observations are needed to confirm and understand the timing variation.

Links

• PREPRINT http://arxiv.org/abs/1903.02573
• ELECTR https://doi.org/10.3847/1538-3881/ab189f
• SIMBAD https://simbad.u-strasbg.fr/simbad/sim-ref?querymethod=bib&simbo=on&submit=submit+bibcode&bibcode=2019AJ....157..217B
• PDF https://iopscience.iop.org/article/10.3847/1538-3881/ab189f/pdf
• DATA http://exoplanetarchive.ipac.caltech.edu/cgi-bin/DisplayOverview/nph-DisplayOverview?type=REFERENCE&bibcode=2019AJ....157..217B
• DATA https://10.5281/zenodo.1160627
• DATA https://10.5281/zenodo.1246769
• DATA https://irsa.ipac.caltech.edu/bibdata/2019/B/2019AJ....157..217B.html