The K2-24 planetary system revisited by CHEOPS

Autor(en): V. Nascimbeni, L. Borsato, P. Leonardi, S. G. Sousa, T. G. Wilson, A. Fortier, A. Heitzmann, G. Mantovan, R. Luque, T. Zingales, G. Piotto, Y. Alibert, R. Alonso, T. Bárczy, D. Barrado Navascues, S. C.C. Barros, W. Baumjohann, T. Beck, W. Benz, N. Billot, F. Biondi, A. Brandeker, C. Broeg, M. D. Busch, A. Collier Cameron, A. C.M. Correia, Sz Csizmadia, P. E. Cubillos, M. B. Davies, M. Deleuil, A. Deline, L. Delrez, O. D.S. Demangeon, B. O. Demory, A. Derekas, B. Edwards, D. Ehrenreich, A. Erikson, L. Fossati, M. Fridlund, D. Gandolfi, K. Gazeas, M. Gillon, M. Güdel, M. N. Günther, Ch Helling, K. G. Isaak, F. Kerschbaum, L. L. Kiss, J. Korth, K. W.F. Lam, J. Laskar, A. Lecavelier Des Etangs, A. Leleu, M. Lendl, D. Magrin, P. F.L. Maxted, B. Merín, C. Mordasini, G. Olofsson, R. Ottensamer, I. Pagano, E. Pallé, G. Peter, 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, R. Southworth, M. Stalport, S. Sulis, Gy M. Szabó, S. Udry, B. Ulmer, V. Van Grootel, J. Venturini, E. Villaver, N. A. Walton
Abstrakt: The planetary system K2-24 is composed of two transiting low-density Neptunians locked in an almost perfect 2:1 resonance and showing large transit time variations (TTVs), and it is an excellent laboratory to search for signatures of planetary migration. Previous studies performed with K2, Spitzer, and RV data tentatively claimed a significant non-zero eccentricity for one or both planets, possibly high enough to challenge the scenario of pure disk migration through resonant capture. With 13 new CHEOPS light curves (seven of planet b, six of planet c), we carried out a global photometric and dynamical re-analysis by including all the available literature data as well. We obtained the most accurate set of planetary parameters to date for the K2-24 system, including radii and masses at 1% and 5% precision (now essentially limited by the uncertainty on stellar parameters) and non-zero eccentricities e_b = 0.0498_-0.0018^+0.0011, e_c = 0.0282_-0.0007^+0.0003 detected at very high significance for both planets. Such relatively large values imply the need for an additional physical mechanism of eccentricity excitation during or after the migration stage. Also, while the accuracy of the previous TTV model had drifted by up to 0.5 days at the current time, we constrained the orbital solution firmly enough to predict the forthcoming transits for the next ~15 years, thus enabling efficient follow-up with top-level facilities such as JWST or ESPRESSO.
Organisation(en): Institut für Astrophysik
Externe Organisation(en): INAF - Osservatorio Astronomico di Padova, Università degli Studi di Padova, Università degli Studi di Trento, Universidade do Porto, University of Warwick, Universität Bern, Universität Genf, University of Chicago, Instituto de Astrofísica de Canarias (IAC), Universidad de La Laguna, Admatis, Centro de Astrobiología (CSIC-INTA), Österreichische Akademie der Wissenschaften (ÖAW), Max-Planck-Institut für extraterrestrische Physik, Stockholm University, University of St. Andrews, Universidade de Coimbra, Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), INAF-Osservatorio Astrofisico di Torino, Lund University, Aix-Marseille Université, Université de Liège, Katholieke Universiteit Leuven, Eötvös Loránd University Budapest, SRON Netherlands Institute for Space Research , Leiden University, Chalmers University of Technology, Università degli Studi di Torino, National & Kapodistrian University of Athens, European Space Research & Technology Centre (ESA/ESTEC), Technische Universität Graz, MTA Társadalomtudományi Kutatóközpont, Lund Observatory, Université de recherche Paris Sciences et Lettres, Université Paris VI - Pierre-et-Marie-Curie, Keele University, European Space Astronomy Centre (ESA), INAF-Osservatorio Astrofisico di Catania, Eidgenössische Technische Hochschule Zürich, University of Cambridge, Freie Universität Berlin (FU), Spanish National Research Council (CSIC), Institut d'Estudis Espacials de Catalunya (IEEC), European Space Agency (ESOC) Germany, HUN-REN Magyar Kutatási Hálózat
Journal: Astronomy and Astrophysics
Band: 690
Anzahl der Seiten: 16
ISSN: 0004-6361
DOI: https://doi.org/10.1051/0004-6361/202450852
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/1d1126d1-14fb-485a-8818-44a90fd41713

Zurück