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Jorge Fernández-Fernández

I am a first year PhD student in the Astronomy and Astrophysics group at the University of Warwick. My supervisor is Prof Peter Wheatley. I am studying how the evolution of close-in exoplanets is affected by the high energy radiation coming from their host stars.

Research Interests

The Kepler mission has uncovered a surprising number of planets between Earth and Neptune in size that are not present in our Solar System. The masses and sizes of some of these planets are consistent with a solid rocky core surrounded by a large H-rich envelope (mini-Neptunes) that can double the planet's radius and yet comprise less than a percent of its mass; whereas others are most likely entirely rocky (super-Earths). These two populations appear as two distinct peaks in the radius distribution of Kepler planets, the Radius Gap.

Photoevaporation, a leading hypothesis in the field, proposes that high energy radiation emitted by their host stars, namely X-rays and Extreme Ultraviolet (together XUV), is readily absorbed by the upper layers of the planet's atmospheres. This causes the envelopes to heat-up and expand to several planetary radii, with the subsequent escape of material from the planet's gravitational influence. This process has been directly observed in Lyman-α transits, in which the extended atmosphere occults a larger amount of stellar photons than expected given the planet's optical radius.

My research focuses on studying the extent to which photoevaporation influences the evolution of young close-in mini-Neptunes and super-Earths.


  • Astrophysics, PhD. University of Warwick (2020-). "Characterisation of the X-ray emission of stars in order to assess the evolution of planetary atmospheres".
  • Physics with Astrophysics, MPhys. University of Exeter (2016-2020). Integrated Masters program, combining a 3-year bachelors degree with a final year masters dissertation. "Direct Imaging of Exoplanets & Circumstellar Discs". Supervised by Dr. Sasha Hinkley.

Conferences / Workshops

  • XMM-Newton 2021 Science Workshop (May 2021). Analysis of X-ray driven atmospheric loss on three-planet system K2-136.
  • STFC Introduction to Astronomy (January 2021). Analysis of X-ray driven atmospheric loss on multiplanetary system K2-136. Link to presentation here.
  • UKEXOM (April 2021)
  • ESCAPE Data Science Summer School (June 2021)


First Author
Contributing Author


Picture of Jorge on a sunny day wearing a coat. Taken at the Eden Project, Cornwall.

Write to:

Jorge Fernández Fernández,

Department of Physics,
University of Warwick,
Coventry CV4 7AL

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