David Ehrenreich obtained his PhD in 2007 from Sorbonne Université in Paris, where he worked on exoplanetary atmospheres at Institut d'Astrophysique de Paris. After a postdoctoral stay at Institut de Planétologie et d'Astrophysique de Grenoble, he joined the Department of Astronomy at Université de Genève in 2012. He is an Associate Professor in the Department since 2017. He is studying sunsets on distant planets around other stars, hoping to find traces of life in their atmospheres.

Extrasolar sunsets can only be observed when the planet is transiting across the stellar disc, as seen from the Earth. When sunlight passes through the atmospheric limb of the Earth, it is absorbed and scattered by gas, dust, and clouds, producing a coloured vista such as the one pictured above (a sunset on Earth as seen from the International Space Station). His research work focuses on observing and modelling such colours for "sunsets" on planets revolving around other stars, also known as exoplanets.  Measuring their colours with spectroscopy is a powerful way to determine the atmospheric properties of these alien worlds, which is his main research interest. 

David Ehrenreich was a CNES and a Marie Skłodowska Curie fellow; in 2016, he received a Consolidator grant from the European Research Council (ERC). Today, he is the chairperson of the CHEOPS Science Team. CHEOPS is a small mission of the European Space Agency (ESA) and a partnership between ESA and an international consortium led by Switzerland. It follows up the most interesting exoplanets in the sky in search for their transit, performing first-step characterisation of these remote worlds (are they gaseous, icy, or rocky planets?). He is the Principal Investigator of a project funded by the Swiss National Science Foundation called "Spectroscopy of hot twilights in exoplanetary atmospheres". The project is co-led by Prof. Vincent Bourrier. David Ehrenreich is also a project leader within the National Centre for Competencies in Research called PlanetS.

At the Department of Astronomy, he is contributing to the CHEOPS, ESPRESSO, NIRPS, HARPS-N, RISTRETTO and ANDES projects and is a regular user of the Hubble Space Telescope.

David Ehrenreich is a member of the Centre Vie dans l'Univers / Life in the Universe of the Faculty of Science of Université de Genève. He is also a member of the Space Research Committee of the Swiss Academy of Natural Sciences. He is the author of more than 200 scientific articles (list of publications on NASA Astrophysical Data System).

He is responsible for the exhibition Exoplanets – Art, Science & Fiction, which opened in the city of Versoix (GE) during Winter 2023.

Research group

David Ehrenreich's group is currently composed of the following researchers,

• Dr Adrien Deline (SNF research & teaching fellow)
• Dr Stefan Pelletier (NCCR PlanetS research & teaching fellow)
• Michal Steiner (SNF research & teaching assistant)
• Valentina Vaulato (NCCR PlanetS research & teaching assitant)

Previous team members:

• Dr William Pluriel (2021-2023)
• Dr Leonardo Dos Santos (2017-2021; now assistant astronomer at the Space Telescope Science Institute in Baltimore, USA)
• Dr Julia Seidel (2017-2021; now fellow at the European Southern Observatory in Santiago, Chile)
• Dr Martin Turbet (2018-2021; now permanent researcher at Laboratoire de Météorologie Dynamique, Paris)
• Dr Lorenzo Pino (2014-2018; now a permanent researcher at Osservatorio Astrofisico di Arcetri)
• Dr Thibault Kuntzer (2018-2019; now a data scientist at Identitas)
• Dr Baptiste Lavie (2014-2019; now a postdoctoral researcher with Prof. Francesco Pepe)
• Dr Jens Hoeijmakers (2017-2020; now an associate senior lecturer at Universitet Lunds)
• Dr Laetitia Delrez (visiting researcher in 2020-2021; now a postdoctoral researcher at Univeristé de Liège)
• Dr Vincent Bourrier (2014-2021; now an ERC grantee and assistant professor at UNIGE)