2020/02/07 by Kishore C. Patra, Joshua N. Winn, Matthew J. Holman +15 · 2 citations
Physics and Astronomy · #astro-ph.EP #astro-ph.SR
paper · pdf · doi:10.3847/1538-3881/ab7374
16 pages, 26 figures, accepted for publication in AJ
arxiv created 2020/02/07 · arxiv updated 2020/03/18
Many of the known hot Jupiters are formally unstable to tidal orbital decay. The only hot Jupiter for which orbital decay has been directly detected is WASP-12, for which transit timing measurements spanning more than a decade have revealed that the orbital period is decreasing at a rate of dP/dt≈ 10-9, corresponding to a reduced tidal quality factor of about 2× 105. Here, we present a compilation of transit-timing data for WASP-12 and eleven other systems which are especially favorable for detecting orbital decay: KELT-16; WASP-18, 19, 43, 72, 103, 114, and 122; HAT-P-23; HATS-18; and OGLE-TR-56. For most of these systems we present new data that extend the time baseline over which observations have been performed. None of the systems besides WASP-12 displays convincing evidence for period changes, with typical upper limits on dP/dt on the order of 10-9 or 10-10, and lower limits on the reduced tidal quality factor on the order of 105. One possible exception is WASP-19, which shows a statistically significant trend, although it may be a spurious effect of starspot activity. Further observations are encouraged.