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.
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
- STFC Introduction to Astronomy (January 2021). Analysis of X-ray driven atmospheric loss on multiplanetary system K2-136. Link to presentation here.
- XMM-Newton 2021 Science Workshop (May 2021). Analysis of X-ray driven atmospheric loss on three-planet system K2-136.
- UKEXOM (April 2021)
- ESCAPE Data Science Summer School (June 2021)
Discovery of an Edge-on Circumstellar Debris Disk Around BD+45° 598: a Newly Identified Member of the β Pictoris Moving Group. S. Hinkley et al., 2021, The Astrophysical Journal, Volume 912, Issue 2, id.115,
- PX129 (Physics Tutorial) - First year physics problem classes (2020-2021). Marking problem sheets, assessing the progress of undergraduate students, and delivering a teaching session twice a week both in online and face-to-face formats.
Jorge Fernández Fernández,