Institute of Astronomy

- Ryan MacDonald


Personal Homepage

Office: Hoyle H27
Office Tel: (01223) 766653
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Research Themes: Star Formation and Exoplanets

Research Keywords: Planets, Spectroscopy, Theory


My research focuses on the atmospheric characterisation of transiting extrasolar planets. I work with Dr Nikku Madhusudhan to develop new atmospheric retrieval tools to extract the atmospheric properties (chemical composition, temperature, clouds etc.) of exoplanets.

Further information on my research can be found on my personal website.

Research highlights

  • First evidence of metal hydrides (TiH / CrH) in an exoplanet atmsosphere.
  • First detection of titanium oxide (TiO) in an exoplanet atmosphere.
  • First evidence of nitrogen chemistry (NH3 / HCN) in hot Jupiter exoplanet atmospheres.

Selected papers

  1. MacDonald, R.J. & Madhusudhan, N., 2019, The Metal-Rich Atmosphere of the Exo-Neptune HAT-P-26b - MNRAS 486, 1292
  2. MacDonald, R.J., Marley, M.S., Fortney, J.J., & Lewis N.K., 2018, 'Exploring H2O Prominence in Reflection Spectra of Cool Giant Planets' - ApJ 858, 69
  3. MacDonald, R.J. & Madhusudhan, N., 2017, 'Signatures of Nitrogen Chemistry in Hot Jupiter Atmospheres' - ApJL 850, L15
  4. Sedaghati, E., Boffin, H.M.J., MacDonald, R.J., et al., 2017, 'Detection of titanium oxide in the atmosphere of a hot Jupiter' - Nature 549, 238
  5. MacDonald, R.J. & Madhusudhan, N., 2017, 'HD 209458b in New Light: Evidence of Nitrogen Chemistry, Patchy Clouds and Sub-Solar Water'MNRAS 469, 1979


2015-Present: PhD in Astronomy (Cambridge)

Supervisor: Dr Nikku Madhusudhan

Project: Inverse Modelling Methods for the Characterisation of Exoplanetary Atmospheres

2016: Kavli Summer Program in Astrophysics Fellow (UC Santa Cruz)

Supervisor: Dr Mark S. Marley

Project: Water Absorption Signatures in Cool Giant Planets

2015: Masters Research Student (Oxford)

Supervisors: Dr Neil Bowles & Dr Kerri Donaldson Hanna

Project: Phobos Sample Return via Thermal-IR Profiling

2014: Venus Express Data Analyst (Oxford)

Supervisor: Dr Colin Wilson

Project: Correlations Between Temperature Structure and UV Contrasts in the Clouds of Venus



PhD, Astronomy - University of Cambridge (2015-present)

MPhys, Physics (1st Class) - University of Oxford (2011-2015)

Awards and Prizes

2017: Paul Murdin Prize - Best published journal paper produced by a current Cambridge Institute of Astronomy Ph.D. student (joint award).

Page last updated: 26 April 2019 at 11:58