We are pleased to announce the SUBSTELLAR ASTROPHYSICS 2026 international conference to be held in the week 10-14 August near the historic town of Tordesillas, Castilla, Spain.

This conference will bring together researchers interested in Substellar science with special emphasis on exploiting the wealth of data provided by ESA Euclid Space mission complemented with other surveys and follow-up observations.

Substellar science has emerged in the last few decades as a new branch of Astrophysics that connects Stars, Exoplanets and the Solar System. The advent of new surveys such as Euclid, Nancy Green Roman Space Telescope and Rubin LSST is poised to increase the numbers of known substellar objects by more than an order of magnitude, while the James Webb Telescope is providing new details about their properties. Rapid advances in observational capabilities have spurred the development of a new generation of theoretical models, now reaching unprecedented levels of accuracy and physical completeness. A total eclipse of the Sun will take place during the conference (August 12, 2026).

Program highlights

Key themes include:

• Detection methods (Searching methods, astrometry, photometry, spectroscopy)
• Confirmation of UCD candidates
• Atmospheric properties of UCD's
• UCD in connection with Milky Way
• Multiplicity, planetary systems, disks
• Substellar luminosity and mass functions
• Connection with exoplanets
• Synergies of Euclid and other surveys
• Big data, machine learning for substellar science
• Prospects for Exolife in Substellar Worlds
• Theory of UCD's (atmospheric and evolutionary models, microphysics)
• Substellar challenge!

Confirmed invited speakers

• Khalid Barkaoui, Instituto de Astrofísica de Canarias, La Laguna, Tenerife, Spain
• David Barrado, Centro de Astrobiología, Torrejon de Ardoz, Madrid, Spain
• Beth Biller, Royal Observatory, Edinburgh, UK
• Clemence Fontanive, Royal Observatory, Edinburgh, UK
• John Gizis, University of Delaware, USA
• Kevin Luhman, Pennsylvania State University, USA
• Elena Manjavacas, ESA/AURA Astronomer at Space Telescope Science Institute, USA
• Javier Olivares, UNED, Madrid, Spain
• Antonio Pérez Garrido, Universidad Politécnica de Cartagena, Spain
• Rafael Rebolo, Instituto de Astrofísica de Canarias, La Laguna, Tenerife, Spain
• Céline Reylé, Observatoire de Besançon, France
• Richard Smart, Ossevatorio Astrofisico di Torino, INAF, Italy
• Enrique Solano, Centro de Astrobiología, Torrejon de Ardoz, Madrid, Spain
• Xianyu Tan, Shanghai Jiao Tong University, China
• Ramarao Tata, University of Ohio, USA
• Maria Rosa Zapatero Osorio, Centro de Astrobiología, Torrejon de Ardoz, Madrid, Spain
• Jun-Yan Zhang, Western University, Ontario, Canada

Scientific Organizing Committee

• Eduardo Martin (chair)
• Maruša Žerjal (co-chair)
• Nikola Vitas (co-chair)
• Patricia Cruz
• Pin-Gao Gu
• Nuria Huélamo
• Nicolas Lodieu
• Koraljka Mužić
• Ngoc Phan
• Annie Robin
• Johannes Sahlmann
• Kun Wang

Local Organizing Committee

• Alberto Escobar Rodríguez (chair)
• Victor Almendros Abad
• Mariloli Maeso
• Sara Muñoz Torres
• Nafise Sedighi
• Stella Tsilia

Important dates

• Open for preregistration and abstract submission: December 10, 2025
• Close for preregistration and abstract submission: February 15, 2026
• Notification of acceptance, open for registration: March 1, 2026
• Deadline for early registration: April 11, 2026
• Deadline for late registration: June 1, 2026
• Conference dates: August 10 - 14, 2026