Tailong Zhang is a PhD student in the Department of Physics at King’s College London, supervised by Professor Giovanna Tinetti. He studies the atmospheres of exoplanets using transmission spectroscopy - measuring how a planet’s atmosphere filters starlight as it transits its host star. His research applies Bayesian atmospheric retrieval to recover the chemical composition, temperature structure and cloud properties of these atmospheres from spectra taken with facilities such as the James Webb Space Telescope (JWST) and, in future, the ESA Ariel mission. He is particularly interested in minor molecular species - whose abundances trace atmospheric chemistry and may carry imprints of how and where a planet formed. A central theme of his work is degeneracy: separating genuine atmospheric signals from the confounding effects of clouds, hazes and stellar contamination, and quantifying what current and upcoming data can and cannot constrain.

Before joining King’s, Tailong completed an MSc in Planetary Science at University College London and a BSc in Physics and Astronomy at York University, Toronto. He has worked as a Junior Support Scientist at Blue Skies Space Ltd, supporting the Twinkle and Mauve space missions.

Research Interests

• Exoplanet atmospheres and transmission spectroscopy
• Bayesian atmospheric retrieval and nested sampling
• Linking planet formation and chemistry to observed atmospheric abundances

Tailong’s research uses transmission spectroscopy and Bayesian retrieval to infer the chemical make-up of exoplanet atmospheres and to ask what those abundances reveal about a planet’s origin. Working primarily with atmospheric retrieval, he models how molecules shape a planet’s spectrum, and uses nested sampling to quantify how well each can be constrained. A recurring question is whether elemental ratios such as C/O and metallicity can be connected back to where in a protoplanetary disc a planet assembled, and how cleanly that link survives the degeneracies introduced by clouds, hazes and stellar activity. His work sits at the intersection of atmospheric chemistry, planet formation and disk chemistry, in preparation for the data expected from JWST and the Ariel mission.

Thesis title and abstract

Atmospheric characterisation of exoplanets using transit spectroscopy

Over the past few decades, more than 6,000 exoplanets have been discovered beyond our Solar System, revealing a remarkable diversity of planetary environments. While these worlds vary widely in size and composition, their atmospheres preserve key information about the conditions under which they formed and evolved. This research aims to explore how planetary formation processes and native environments influence the chemical composition of present-day exoplanet atmospheres. Using a suite of atmospheric models, the project will interpret atmospheric properties based on transit spectroscopy, focusing on what can be learned from currently available spectral data. In addition to studying individual planets, population-level analyses will be carried out using exoplanet atmospheric spectra to identify broader trends linking atmospheric characteristics with planetary origins and environmental conditions.

Supervisors

Primary: Professor Giovanna Tinetti

Secondary: Dr Gordon Yip

Publications

Zhang, T., Wilcock, B., Ma, S., Tinetti, G., Bradley, L., Stotesbury, I., Tessenyi, M., & Tennyson, J. (2025). Atmospheric Characterisation with the Twinkle Space Telescope Following Advances from JWST Observations. RASTI, accepted. arXiv:2508.10386

Personal website: https://tailongzhang.github.io