MATISSE unveils a dusty disc in the interior of EP Aquarii. First evidence of a misaligned hierarchical triple system with a central AGB star?

@misc{alonsohernandez2026matisse,
  title = {{MATISSE unveils a dusty disc in the interior of EP Aquarii. First evidence of a misaligned hierarchical triple system with a central AGB star?}},
  author = {J. Alonso-Hernández and C. Paladini and C. Sánchez Contreras and J. Drevon and J. P. Fonfría and L. Planquart and T. Khouri and L. Siess and A. Jorissen and B. Aringer and F. Baron and E. De Beck and S. Höfner and J. Hron and F. Lykou and F. Millour and M. Montargès and N. Nardetto and K. Ohnaka and H. Olofsson and V. Răstău and J. Sanchez-Bermudez and L. Velilla-Prieto and W. Vlemmings and M. Wittkowski and G. Weigelt and W. C. Danchi and F. Kerschbaum and B. Lopez},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2610.18134},
  eprint = {2610.18134},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2610.18134},
  note = {CC BY-NC-SA 4.0},
}

TY  - UNPB
TI  - MATISSE unveils a dusty disc in the interior of EP Aquarii. First evidence of a misaligned hierarchical triple system with a central AGB star?
AU  - J. Alonso-Hernández
AU  - C. Paladini
AU  - C. Sánchez Contreras
AU  - J. Drevon
AU  - J. P. Fonfría
AU  - L. Planquart
AU  - T. Khouri
AU  - L. Siess
AU  - A. Jorissen
AU  - B. Aringer
AU  - F. Baron
AU  - E. De Beck
AU  - S. Höfner
AU  - J. Hron
AU  - F. Lykou
AU  - F. Millour
AU  - M. Montargès
AU  - N. Nardetto
AU  - K. Ohnaka
AU  - H. Olofsson
AU  - V. Răstău
AU  - J. Sanchez-Bermudez
AU  - L. Velilla-Prieto
AU  - W. Vlemmings
AU  - M. Wittkowski
AU  - G. Weigelt
AU  - W. C. Danchi
AU  - F. Kerschbaum
AU  - B. Lopez
PY  - 2026
DA  - 2026/10/13
PB  - arXiv
DO  - 10.48550/arxiv.2610.18134
UR  - https://arxiv.org/abs/2610.18134
AB  - Aims. We have mapped the dust and molecular gas emission distributions in the vicinity (a few stellar radii) of the asymptotic giant branch (AGB) star EP\,Aquarii, with 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\,\mum) as well as archival high-angular-resolution (≳20\,mas) ALMA ^12CO\,(cJ=2-1) line and continuum emission observations (∼230\,GHz), to study 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 ^12CO\,(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), hinting the presence of a close (≲4\,au) companion. The inferred symmetry axis is almost perpendicular to the CO velocity gradient and the orbital plane proposed for the distant (∼50\,au) companion. EP\,Aqr may represent the first misaligned hierarchical triple system with a central AGB star.
ER  -