Science cases for a visible interferometer

Philippe Stee, France Allard, Myriam Benisty, Lionel Bigot, Nicolas Blind, Henri Boffin, Marcelo Borges Fernandes, Alex Carciofi, Andrea Chiavassa, Orlagh Creevey, Pierre Cruzalebes, Willem-Jan de Wit, Armando Domiciano de Souza, Martin Elvis, Nicolas Fabas, Daniel Faes, Alexandre Gallenne, Carlos Guerrero Pena, Michel Hillen, Sebastian Hoenig, Michael Ireland, Pierre Kervella, Makoto Kishimoto, Nadia Kostogryz, Stefan Kraus, Antoine Labeyrie, Jean-Baptiste Le Bouquin, Agnès Lebre, Roxanne Ligi, Alessandro Marconi, Thomas Marsh, Anthony Meilland, Florentin Millour, John Monnier, Denis Mourard, Nicolas Nardetto, Keiichi Ohnaka, Claudia Paladini, Karine Perraut, Guy Perrin, Pascal Petit, Romain Petrov, Gail Schaefer, Jean Schneider, Denis Shulyak, Michal Simon, Ferreol Soulez, Danny Steeghs, Isabelle Tallon-Bosc, Michel Tallon, Theo ten Brummelaar, Eric Thiebaut, Frédéric Thévenin, Hans Van Winckel, Markus Wittkowski

Published 2017-03-07Version 1

High spatial resolution is the key for the understanding various astrophysical phenomena. But even with the future E-ELT, single dish instruments are limited to a spatial resolution of about 4 mas in the visible. For the closest objects within our Galaxy most of the stellar photosphere remains smaller than 1 mas. With the success of long baseline interferometry these limitations were soom overcome. Today low and high resolution interferometric instruments on the VLTI and CHARA offer an immense range of astrophysical studies. Combining more telescopes and moving to visible wavelengths broadens the science cases even more. With the idea of developing strong science cases for a future visible interferometer, we organized a science group around the following topics: pre-main sequence and main sequence stars, fundamental parameters, asteroseismology and classical pulsating stars, evolved stars, massive stars, active galactic nuclei (AGNs) and imaging techniques. A meeting was organized in January 15 \& 16, 2015 in Nice with the support of the Action Specific in Haute R\'esolution Angulaire (ASHRA), the Programme National en Physique Stellaire (PNPS), the Lagrange Laboratory and the Observatoire de la C\^ote d'Azur, in order to present these cases and to discuss them further for future visible interferometers. This White Paper presents the outcome of the exchanges. This book is dedicated to the memory of our colleague Olivier Chesneau who passed away at the age of 41.