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Subhajit Sarkar

Dr Subhajit Sarkar

Astronomy Group
Astronomy Instrumentation Group
Cardiff Hub for Astrophysics Research and Technology

School of Physics and Astronomy

Queen's Buildings - North Building, Room N/3.22, 5 The Parade, Newport Road, Cardiff, CF24 3AA
Available for postgraduate supervision


I'm a university lecturer and astrophysicist working in the field of extra-solar planets. I am involved in the development of new missions and observatories to characterise the atmospheres of exoplanets, in particular the ESA Ariel mission, as well as Twinkle and the NASA EXCITE mission.  I also am involved in cycle 1 JWST exoplanet observations in collaboration with IoA Cambridge. I am interested in understanding atmospheric and planetary processes in temperate regime sub-Neptunes and gas giants, and how these relate to fundamental questions of planet formation and the diversity of the exoplanet population.  I am also interested in astrobiology, particularly the potential for biospheres in temperate gas giants, modeling of observations to find the frequency of life-bearing worlds (the fL factor in the Drake Equation), and how exoplanetary observations might be able to constrain theories of the origin of life.




















Research focus

  • Development of new exoplanet observatories and missions:
    • Ariel: Ariel Data Reduction Pipeline (ADaRP) development lead, simulations working group lead, spectral retrievals working group, ground segment and calibration working groups.
    • EXCITE: first dedicated phase-curve spectroscopy observatory; First Balloon-Borne Exoplanet Observatory; official NASA collaborator
    • Software developed: ExoSim, ExoSim_N, JexoSim (JWST simulator), TwinkleSim, ADaRP
  • Exoplanet atmospheres
    • JWST transmission spectroscopy
      • Co-I on Cycle 1 GO program 2722:
        'Chemical Disequilibrium in a Temperate sub-Neptune'. Approx. 20 hours. We will use NIRISS, NIRSpec and MIRI to obtain the transmission spectrum of the sub-Neptune K2-18 b from 0.6 to 12 microns.
      • Co-I on Cycle 2 GO program 3557:
        'A JWST Search for Missing Methane'.  Approx. 70 hours.  We will use NIRISS, NIRSpec and MIRI to obtain transmission spectra for 4 sub-Neptune/Neptune-sized planets.
    • Temperate gas giants: (with Luke Booth) developing modeling and observational approaches to characterise this poorly-understood exoplanet population.
    • Twinkle mission: science team member and designated observer for Cardiff, cool gas giant working group. I will be shaping the observation programme of the Twinkle exoplanet atmospheric survey.
  • Astrobiology
    • DRAKE (Dedicated Research for Advancing Knowledge of Exobiology): a proposed space mission to find the frequency of life in the Galaxy using transit spectroscopy (see paper in MNRAS).
    • Aerial biospheres in temperate gas giants: modeling these in preparation for future observations.


Current undergraduate teaching

  • PX4245 / PXT145 Exoplanets and the Search for Life: Module Organiser (new module for Spring 2023)
  • PX2140 Stars and Planets: Deputy Module Organiser

Previous undergraduate teaching

  • PX1127 Planet Earth: Module Organiser
  • PX2140 Stars and Planets: guest lecturer
  • PX1127 Planet Earth: Deputy Module Organiser
  • PX2134 Structured Programming: Lab supervisor
  • PX1125 Mathematical Practice for Physical Sciences: Marker
  • PX1222 Mathematical Methods for Physicists 2: Marker


  • I supervise PhD and MPhys research projects (see supervision page)



  • PhD, Astrophysics, Cardiff University
  • MSc (Distinction), Space Science, University College London
  • Diploma in Physics (Distinction), Open University
  • MA, Natural Sciences, Cambridge University
  • MB, BChir, Medicine, Cambridge University
  • Grad. Cert. Applied Sciences, Space Studies, University of South Australia
  • Space Studies Program, International Space University

Professional memberships

  • Fellow of the Royal Astronomical Society
  • Fellow of the Higher Education Academy

Academic positions

  • 2022- Present: Lecturer, School of Physics and Astronomy, Cardiff University
  • 2017-2021: Post-doctoral Research Associate, Cardiff University
  • 2013-2017: Post-graduate Research Student, Cardiff University
  • 2003-2005: Visiting Researcher, Space Medicine & Health Care Systems Office, NASA Johnson Space Center, Houston.
  • 2003-2005: Honorary Lecturer in Space Life Sciences, Dept. of Space & Climate Physics, University College London

Outreach and Media

  • BBC Radio Wales Science Cafe interview about the ARIEL space mission (April 2018).
  • Pythagorean Astronomy podcast interview about TESS, ARIEL and other exoplanet missions (April 2018).
  • Exoplanet talks for Cardiff AS Level Summer Programmes 2018/19.
  • Stargazing talk and telescope observing with Scouts (Spring 2019).
  • Online astronomy talk with Scouts (Winter 2020).
  • 'All About Space' magazine interview about Ariel mission ('Rise of the Exoplanet Hunter') (Jan 2021).
  • Twinkle mission YouTube video ('The Founding Members') (Aug 2021).
  • Pythagorean Astronomy podcast interview about JWST observing programme (Dec 2021).
  • Cardiff School of Physics & Astronomy YouTube video about JWST (Dec 2021).
  • BBC News Wales interview about exoplanets and JWST (July 2022).
  • Nature News and Views article on JWST (Feb 2023).

Committees and reviewing

I currently serve on the following school committees:  a) Equality, diversity and inclusion (EDI), b) Ethics, c) Environment and sustainability. I am on also the CHART-GEI Schools Engagement Project management team. 


Current supervision

  • I am primary PhD supervisor for Luke Booth who is researching exoplanet atmospheres.
  • I am currently on the supervisory team as mentor for two PhD students.
  • I currently supervise the 3rd year project "Missions to the planets" and the 4th year project "Habitable exomoons"

Current supervision

Luke Booth

Mr Luke Booth

Research student