HR 10 as seen by CHEOPS and TESS

Autor(en)

S. J.A.J. Salmon, V. Van Grootel, S. Sulis, Gy M. Szabó, A. Brandeker, C. Broeg, D. Ehrenreich, S. Hoyer, S. G. Sousa, F. Kiefer, D. Gandolfi, D. Nardiello, S. Charpinet, A. Bonfanti, T. G. Wilson, Y. Alibert, R. Alonso, G. Anglada, T. Bárczy, D. Barrado Navascues, S. C.C. Barros, W. Baumjohann, M. Beck, T. Beck, W. Benz, N. Billot, X. Bonfils, L. Borsato, J. Cabrera, V. Cessa, S. Charnoz, A. Collier Cameron, C. Corral Van Damme, Sz Csizmadia, P. E. Cubillos, M. B. Davies, M. Deleuil, L. Delrez, O. D.S. Demangeon, B. O. Demory, A. Erikson, A. Fortier, L. Fossati, M. Fridlund, M. Gillon, M. Güdel, J. Hasiba, K. G. Isaak, L. L. Kiss, J. Laskar, A. Lecavelier Des Etangs, M. Lendl, C. Lovis, D. Magrin, P. F.L. Maxted, C. Mordasini, V. Nascimbeni, G. Olofsson, R. Ottensamer, I. Pagano, E. Pallé, G. Peter, G. Piotto, D. Pollacco, D. Queloz, R. Ragazzoni, N. Rando, H. Rauer, I. Ribas, N. C. Santos, G. Scandariato, D. Ségransan, A. E. Simon, A. M.S. Smith, M. Steller, N. Thomas, S. Udry, J. Venturini, V. Viotto, I. Walter, N. A. Walton

Abstrakt

Context. HR 10 has only recently been identified as a binary system. Previously thought to be an A-type shell star, it appears that both components are fast-rotating A-type stars, each presenting a circumstellar envelope. Although showing complex photometric variability, spectroscopic observations of the metallic absorption lines reveal variation explained by the binarity, but not indicative of debris-disc inhomogeneities or sublimating exocomets. On the other hand, the properties of the two stars make them potential δ Scuti pulsators. Aims. The system has been observed in two sectors by the TESS satellite, and was the target of three observing visits by CHEOPS. Thanks to these new data, we aim to further characterise the stellar properties of the two components. In particular, we aim to decipher the extent to which the photometric variability can be attributed to a stellar origin. In complement, we searched in the lightcurves for transient-type events that could reveal debris discs or exocomets. Methods. We analysed the photometric variability of both the TESS and CHEOPS datasets in detail. We first performed a frequency analysis to identify and list all the periodic signals that may be related to stellar oscillations or surface variability. The signals identified as resulting from the stellar variability were then removed from the lightcurves in order to search for transient events in the residuals. Results. We report the detection of δ Scuti pulsations in both the TESS and CHEOPS data, but we cannot definitively identify which of the components is the pulsating star. In both datasets, we find flicker noise with the characteristics of a stellar granulation signal. However, it remains difficult to firmly attribute it to actual stellar granulation from convection, given the very thin surface convective zones predicted for both stars. Finally, we report probable detection of transient events in the CHEOPS data, without clear evidence of their origin.

Organisation(en)

Institut für Astrophysik

Externe Organisation(en)

Universität Genf, Université de Liège, Aix-Marseille Université, Eötvös Loránd University Budapest, Stockholm University, Universität Bern, Universidade do Porto, Centre National De La Recherche Scientifique (CNRS), Université de recherche Paris Sciences et Lettres, CNRS Institut écologie et environnement, Università degli Studi di Torino, Université Grenoble-Alpes, Università degli Studi di Padova, Université de Toulouse, Österreichische Akademie der Wissenschaften (ÖAW), University of St. Andrews, Instituto de Astrofísica de Canarias (IAC), Universidad de La Laguna, Spanish National Research Council (CSIC), Institut d'Estudis Espacials de Catalunya (IEEC), Admatis, Centro de Astrobiología (CSIC-INTA), INAF - Osservatorio Astronomico di Padova, Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Université de Paris, European Space Research & Technology Centre (ESA/ESTEC), INAF-Osservatorio Astrofisico di Torino, Lund University, Leiden University, Chalmers University of Technology, MTA Társadalomtudományi Kutatóközpont, Université Paris VI - Pierre-et-Marie-Curie, Keele University, INAF-Osservatorio Astrofisico di Catania, University of Warwick, Eidgenössische Technische Hochschule Zürich, University of Cambridge, Technische Universität Berlin, Freie Universität Berlin (FU)

Journal

Astronomy and Astrophysics

Band

690

Anzahl der Seiten

18

ISSN

0004-6361

DOI

https://doi.org/10.1051/0004-6361/202346180

Publikationsdatum

10-2024

Peer-reviewed

Ja

ÖFOS 2012

103003 Astronomie, 103004 Astrophysik

Schlagwörter

ASJC Scopus Sachgebiete

Astronomy and Astrophysics, Space and Planetary Science

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/9d8a27ca-0581-4a43-83b9-459775ab04dc