MATISSE unveils a dusty disc in the interior of EP Aquarii
Year: 2026
Type: article
Abstract: Aims. We mapped the dust and molecular gas emission distributions in the vicinity (a few stellar radii) of the asymptotic giant branch (AGB) star EP Aquarii, which has a previously reported stellar companion at ∼50 au, to search for binary-induced asymmetries. Methods. We present an analysis of new high-angular-resolution (≳4 mas) images obtained with MATISSE (in the wavelength range ∼3–8 μm) as well as archival high-angular-resolution (≳20 mas) ALMA observations, including 12 CO ( J = 2-1) line and continuum emission at ∼230 GHz. We describe the circumstellar morphology and kinematics of the molecular gas on these spatial scales. Results. The MATISSE images display a bright central source and two slightly extended emission features (‘blobs’) located on opposite sides of the AGB star (at radial distances of ∼4–10 au). These structures are consistent with previous mid-infrared interferometric observations, suggesting stability over decades. The central source is elongated along the direction defined by the blobs, in both the MATISSE and ALMA continuum images. The ALMA 12 CO ( J = 2-1) maps display an asymmetric inner wind with a velocity gradient. Conclusions. The observations are consistent with an edge-on dusty equatorial overdensity (disc-like) and thus hint at the presence of a close (≲4 au) companion. The inferred symmetry axis is perpendicular to the CO velocity gradient and the orbital plane proposed for the distant (∼50 au) companion. EP Aquarii may represent the first misaligned hierarchical triple system with a central AGB star.
Source: Astronomy and Astrophysics
Authors: J. Alonso-Hernández, C. Paladini, C. Sánchez Contreras, J. Drevon, J. P. Fonfría, L. Planquart, T. Khouri, L. Siess, A. Jorissen, B. Aringer, F. Baron, E. De Beck, S. Höfner, J. Hron, F. Lykou, F. Millour, M. Montargès, N. Nardetto, K. Ohnaka, H. Olofsson, V. Răstău, J. Sanchez-Bermudez, L. Velilla-Prieto, W. Vlemmings, M. Wittkowski, G. Weigelt, W. C. Danchi, F. Kerschbaum, B. Lopez
Institutions: Centro de Astrobiología, Universidad Autónoma de Madrid, European Southern Observatory, European Southern Observatory, Instituto de Física Fundamental, Chalmers University of Technology, Université Libre de Bruxelles, University of Vienna, Uppsala University, Konkoly Observatory, HUN-REN Research Centre for Astronomy and Earth Sciences, Centre National de la Recherche Scientifique, Université Côte d'Azur, Lagrange Laboratory, Observatoire de la Côte d’Azur, Université Paris Sciences et Lettres, Observatoire de Paris, Sorbonne Université, Universidad Andrés Bello, Universidad Nacional Autónoma de México, Max Planck Institute for Radio Astronomy, Goddard Space Flight Center, Astrophysics Division
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,865
Funders: National Science Foundation, National Radio Astronomy Observatory, European Commission, Korea Astronomy and Space Science Institute, Knut och Alice Wallenbergs Stiftelse, European Southern Observatory, Ministerio de Ciencia e Innovación, National Astronomical Observatory of Japan, Instituto Nacional de Técnica Aeroespacial, National Science and Technology Council, European Research Council, National Institutes of Natural Sciences, European Regional Development Fund, Agencia Estatal de Investigación
OpenAlex ID: W7221809027