摘要
Hot Jupiters should initially form at considerable distances from host stars and subsequently migrate towards inner regions, supported directly by transit timing variation (TTV). We report the TTV of K2-237b, using reproduced timings fitted from Kepler K2 and TESS data. The timings span from 2016 to 2021, leading to an observational baseline of 5 yr. The timing evolution presents a significant bias to a constant period scenario. The model evidence is evaluated utilizing the Bayesian Information Criterion (BIC), which favours the scenario of period decay with a ΔBIC of 14.1. The detected TTV induces a period decay rate (P˙) of -1.14±0.28×10−8 d per day (−0.36 s/yr). Fitting the spectral energy distribution, we find infrared excess at the significance level of 1.5 σ for WISE W1 and W2 bands, and 2 σ level for W3 and W4 bands. This potentially reveals the existence of a stellar disc, consisting of hot dust at 800 ± 300 K, showing a Ldust/L∗ of 5 ± 3×10−3. We obtain a stellar age of 1.0+1.4−0.7×109 yr from isochrone fitting. The properties of K2-237b potentially serve as a direct observational support to the planet disc migration though more observation are needed.