Xuan JiGraduate Student

Research Focus:

Exoplanets; Planetary Climate

Email:

xuanji@uchicago.edu

Biography

BS in Astronomy, Beijing Normal University, 2020

 

Research Interests

My research centers around how the coupled evolution of planetary atmospheres, orbits and stars governs habitability. My goal as a researcher is to uncover what types of planetary architectures favor habitability, which provides a more holistic perspective than analyzing planets' parameters only. The final architectures of planetary systems result from the processes that are critical to habitability, such as accreting building blocks for planet formation, volatile delivery and loss, orbital evolution, and the associated climate evolution. I am generally interested in how these processes shape the habitability. 

My proposed PhD thesis is to investigate the effects of orbital eccentricity and its evolution on planetary climate, with focuses on defining the inner edge of the habitable zone and eccentricity-driven snowball bifurcation. I craft low-order mathematical models, serving as a simplified framework to capture the essence of climate dynamics, and I also uses Global Climate Models (GCMs) for a more comprehensive investigation of complex climate feedback mechanisms. 

In addition to my thesis work, I am working on two side projects right now: studying how outgassed atmosphere of magma planets depends on their distance from their star, and investigating how sweeping secular resonances driven by eccentric gas giant contributes to the formation of water-rich planets. 

 

Publications

Ji, X., and D.S. Abbot (in prep): Snowball Bifurcation Vanishes with Increasing Eccentricity.

Ji, X., R.D. Chatterjee, B. Park Coy and E.S. Kite, 2025 : The Cosmic Shoreline Revisited: A Metric for Atmospheric Retention Informed by Hydrodynamic Escape, arXiv, arXiv:2504.19872. doi:10.48550/arXiv.2504.19872.

Ji, X., N. Bailey, D. Fabrycky, E.S. Kite, J.H. Jiang and D.S. Abbot, 2023: Inner Habitable Zone Boundary for Eccentric Exoplanets. The Astrophysical Journal Letters, 943(1), p.L1. https://doi.org/10.3847/2041-8213/acaf62.

Williams, D.A. X. Ji, P. Corlies and J.M. Lora, 2024: The Effects of Rotation Rate on Clouds on Terrestrial Planets. The Astrophysical Journal, 963, 36, https://doi.org/10.3847/1538-4357/ad192f.

Gu, J.T., B. Peng, X. Ji, J. Zhang, H. Yang, S. Hoyos, MM. Hirschmann, E.S. Kite, and R.A.Fischer 2024: Earth’s Earliest Atmosphere and Volatile Loss During Accretion. Earth and Planetary Science Letters, 629, 118618

Jiang, J. H., X. Ji, N. Cowan, R. Hu, and Z. Zhu, 2019: Empirical predictions for the period distribution of planets to be discovered by the Transiting Exoplanet Survey Satellite. The Astronomical Journal,158 (2), 96

Jiang, J. H., R. Burn, X. Ji, K. A. Fahy, and P. Eggenberger, 2022: Angular momentum distributions for observed and modeled exoplanetary systems. The Astrophysical Journal,924 (2), 118,

Jiang, J. H., D. Zhao, X. Ji, B. Xie, and K. A. Fahy, 2021: Revisiting the planet mass and stellar metallicity relation for low-mass exoplanets orbiting GKM class stars. Universe,7 (4)

Cao, S., M. Biesiada, J. Qi, Y. Pan, X. Zheng, T. Xu, X. Ji, and Z.-H. Zhu, 2018: Cosmological investigation of multi-frequency VLBI observations of ultra-compact structure in z∼3 radio quasars. European Physical Journal C,78 (9), 749

Liu, T., S. Cao, J. Zhang, S. Geng, Y. Liu, X. Ji, and Z.-H. Zhu, 2019: Implications from Simulated Strong Gravitational Lensing Systems. The Astrophysical Journal,886 (2), 94