Denis Defrère
Professor of Astronomy

I am an astronomy professor and researcher at the Institute of Astronomy of KU Leuven in Belgium, where I work towards finding scientific answers to some of the most intriguing questions about our universe. I was previously a Research Associate at the Max Planck Institute for Radio Astronomy (2010-2012), the University Arizona (2012-2026), and the University of Liège (2016-2020), both within the PSILab group and the Liege Space Center.
My scientific interests focus on developing and deploying cutting-edge instruments to directly detect and analyse exoplanets, particularly Earth-like worlds orbiting nearby stars. I am currently involved in the European Southern Observatory (ESO) instrumentation programs. In particular, I am currently the principal investigator of the ERC-funded SCIFY project to build Asgard/NOTT, a new high-contrast instrument for the Very Large Telescope Interferometer (VLTI) at Cerro Paranal in Chile. I also participate in the development and scientific exploitation of GRAVITY+ on the VLTI and am a science team member of METIS, a future infrared imager on the Extremely Large Telescope (ELT). I was previoulsy Instrument scientist of the Large Binocular Telescope Interferometer, a NASA-funded nulling interferometer located in Arizona.
In parallel, I currently serve as Belgium’s representative on the ESO User Committee, where I work to ensure the scientific community’s needs are reflected in ESO’s operations and strategic planning. I also coordinate the Belgian VLTI expertise center and the VLTI joint research activities within the Horizon 2020-funded Opticon RadioNet Pilot (ORP) project, leading efforts to improve access to and user support for the VLTI.
Outside of astrophysics, I enjoy running (betrail) and playing chess.
selected publications
- Asgard/NOTT: L-band nulling interferometry at the VLTI. II. Warm optical design and injection systemJournal of Astronomical Telescopes, Instruments, and Systems, Jan 2024
- High-angular resolution and high contrast observations from Y to L band at the Very Large Telescope Interferometer with the Asgard Instrumental suiteJournal of Astronomical Telescopes, Instruments, and Systems, Apr 2023
- Asgard/NOTT: L-band nulling interferometry at the VLTI. I. Simulating the expected high-contrast performance\aap, Mar 2023
- The HOSTS Survey for Exozodiacal Dust: Observational Results from the Complete Survey\aj, Apr 2020
- Nulling Data Reduction and On-sky Performance of the Large Binocular Telescope Interferometer\apj, Jun 2016
- First-light LBT Nulling Interferometric Observations: Warm Exozodiacal Dust Resolved within a Few AU of \ensuremathη Crv\apj, Jan 2015