About Me

I'm Frances Rigby, a postdoctoral researcher at Imperial College London interested in sub-Neptune exoplanets, those between the size of Earth and Neptune.

I recently completed my PhD at the Institute of Astronomy, University of Cambridge, supervised by Prof. Nikku Madhusudhan. My doctoral research focused on the interiors, atmospheres and habitability of sub-Neptune exoplanets, with my thesis titled Internal Structures in the Sub-Neptune Regime.

I was also a Bye-Fellow of Magdalene College from 2023-24.

Research

  • Sub-Neptunes

    Sub-Neptunes, between the size of Earth and Neptune, are the most abundant class of planet detected, despite the lack of one in our own solar system. My research focuses on this diverse planetary regime.

  • Exoplanet Interiors

    Internal structure modelling is used to relate exoplanet observables to their interior compositions. I use a model developed during my PhD to investigate the possible interior and surface conditions of sub-Neptunes based on their bulk and atmospheric properties.

Publications

A JWST Transmission Spectrum of the Temperate Sub-Neptune TOI-732 c
Frances E. Rigby et al.
Astrophysical Journal Letters, Volume 995, December 2025, Page L70

The Surface and Interior Conditions of Temperate Sub-Neptune TOI-270 d
Frances E. Rigby and Nikku Madhusudhan
Accepted to Monthly Notices of the Royal Astronomical Society

Toward a Self-Consistent Evaluation of Gas Dwarf Scenarios for Temperate Sub-Neptunes
Frances E. Rigby et al.
Astrophysical Journal, Volume 975, Issue 1, November 2024, Page 101

On the Ocean Conditions of Hycean Worlds
Frances E. Rigby and Nikku Madhusudhan
Monthly Notices of the Royal Astronomical Society, Volume 529, Issue 1, March 2024, Pages 409–424

Chemical Conditions on Hycean Worlds
Nikku Madhusudhan, Julianne I. Moses, Frances E. Rigby and Edouard Barrier
Faraday Discussions, Volume 245, 2023, Pages 80-111

Observing Time

JWST Cycle 2 GO Program 3557: A JWST search for missing methane
Nikku Madhusudhan, Julianne I. Moses, Subhajit Sarkar and Frances E. Rigby

Outreach

As a Lindemann Associate I give outreach talks for primary school-age children, covering exoplanets and the search for life.
Read more about the Lindemann Trust here.

Contact

f.rigby@imperial.ac.uk