Congratulations to our visiting graduate student Xian-Yu Wang for passing his remote dissertation defense last week in his home institution, the National Astronomical Observatories of China. Dr. Xian-Yu Wang’s Ph.D. thesis centers on understanding the origin of hot Jupiters by using high-precision photometry and doppler velocimetry to refine subtle clues from the configuration properties of hot Jupiter populations.
He is a key member of Transiting Exoplanet Monitoring Project (TEMP), which collected more than 450 hours of photometric observation of ~40 hot Jupiter systems. He developed analysis algorithms to jointly fit photometric and radial-velocity data to refine the physical and orbital parameters of the systems and to estimate their transit timing variations (TTVs). His analysis indicates that none of the hot Jupiters shows statistically significant TTVs, usually caused by the nearby resonant companions. This conclusion disfavors the disk migration mechanism, which predicted the existence of nearby resonant companions in hot Jupiter systems.
Xian-Yu moved to IU early this year, and is actively involved in IU’s ongoing exoplanet observation project. He developed an algorithm based on MCMC and dynamical integration to model the Rossiter-Mclaughlin effect that emerged from a multi-planet system WASP-148. This method enables a precise characterization of the full orbital parameters of the system, including stellar obliquity. His result found that the hot Jupiter WASP-148b is aligned with the host star’s equator, and a nearby warm Jupiter, whose orbit is mutually inclined by 26°, forming a configuration that has never been seen before. This system provides direct evidence that hot Jupiters could form through quiescent channels, and the observed dynamical hot properties of the hot Jupiter population could be excited by the post-disk dynamical interactions.
His publication can be found online at https://ui.adsabs.harvard.edu/public-libraries/krPxY4SSRi25elahpTuSlg.
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