This Special Session aims to explore the scientific motivations for a next-generation optical/infrared interferometric facility, in the context of ESO?s upcoming Expanding Horizons initiative. As European astronomy looks beyond the ELT era, there is a timely opportunity to assess how optical interferometry could evolve to address fundamental open questions across a wide range of astrophysical domains.

The session is explicitly science-driven and open to contributions from across the astronomical community, including exoplanet science, stellar and Galactic astrophysics, active galactic nuclei, and other areas requiring high-angular-resolution observations. Participants are encouraged to adopt a forward-looking perspective, discussing how their science cases could benefit from interferometric capabilities extending beyond those of current facilities. The goal is not to define a single solution, but rather to explore the breadth of scientific requirements that could inform future developments.

Programme

The session will be organised over one day and structured thematically. The morning programme will focus on science in the near Universe, including exoplanets, stellar systems, compact objects, and Galactic targets. The afternoon programme will address science black-hole physics, and extragalactic science such as active galactic nuclei, galaxy evolution, and related topics.

A lunch session will be devoted to broader discussion of possible facility concepts and long-term directions, providing a forum for open exchange on architectural ideas, community priorities, and potential next steps. Together, these sessions aim to stimulate cross-disciplinary dialogue and to contribute to the emergence of a shared community vision for the future of optical interferometry in Europe.

Invited speakers

Scientific organisers

• Jean-Philippe Berger (IPAG, France)
• Guillaume Bourdarot (MPE, Germany)
• Jean-Philippe Berger (IPAG, France)
• Sebastian Hoenig (University of Southampton, United-Kingdom)
• Foteini Lykou (Konkoly Observatory, Hungary)
• Miguel Montargès (Observatoire de Paris, France)
• Przemek Mróz (University Of Warsow, Poland)
• Nadine Neumayer (MPIA, Germany)
• Mathias Nowak (Observatoire de Paris, France)
• Claudia Paladini (ESO, Chile)

Contact

Mathias Nowak (mathias.nowak @ obspm.fr)
Guillaume Bourdarot (bourdarot @ mpe.mpg.de)