A new dynamical modeling of the WASP-47 system with CHEOPS observations

Autor(en)
V. Nascimbeni, L. Borsato, T. Zingales, G. Piotto, I. Pagano, M. Beck, C. Broeg, D. Ehrenreich, S. Hoyer, F. Z. Majidi, V. Granata, S. G. Sousa, T. G. Wilson, V. Van Grootel, A. Bonfanti, S. Salmon, A. J. Mustill, L. Delrez, Y. Alibert, R. Alonso, G. Anglada, T. Bárczy, D. Barrado, S. C.C. Barros, W. Baumjohann, T. Beck, W. Benz, M. Bergomi, N. Billot, X. Bonfils, A. Brandeker, J. Cabrera, S. Charnoz, A. Collier Cameron, Sz Csizmadia, P. E. Cubillos, M. B. Davies, M. Deleuil, A. Deline, O. D.S. Demangeon, B. O. Demory, A. Erikson, A. Fortier, L. Fossati, M. Fridlund, D. Gandolfi, M. Gillon, M. Güdel, K. G. Isaak, L. L. Kiss, J. Laskar, A. Lecavelier des Etangs, M. Lendl, C. Lovis, R. Luque, D. Magrin, P. F.L. Maxted, C. Mordasini, G. Olofsson, R. Ottensamer, E. Pallé, G. Peter, D. Piazza, D. Pollacco, D. Queloz, R. Ragazzoni, N. Rando, F. Ratti, H. Rauer, I. Ribas, N. C. Santos, G. Scandariato, D. Ségransan, A. E. Simon, A. M.S. Smith, M. Steinberger, M. Steller, Gy M. Szabó, N. Thomas, S. Udry, J. Venturini, N. A. Walton, D. Wolter
Abstrakt

Among the hundreds of known hot Jupiters (HJs), only five have been found to have companions on short-period orbits. Within this rare class of multiple planetary systems, the architecture of WASP-47 is unique, hosting an HJ (planet-b) with both an inner and an outer sub-Neptunian mass companion (-e and -d, respectively) as well as an additional non-transiting, long-period giant (-c). The small period ratio between planets -b and -d boosts the transit time variation (TTV) signal, making it possible to reliably measure the masses of these planets in synergy with the radial velocity (RV) technique. In this paper, we present new space- and ground-based photometric data of WASP-47b and WASP-47-d, including 11 unpublished light curves from the ESA mission CHaracterising ExOPlanet Satellite (CHEOPS). We analyzed the light curves in a homogeneous way together with all the publicly available data to carry out a global N-body dynamical modeling of the TTV and RV signals. We retrieved, among other parameters, a mass and density for planet -d of Md = 15.5 ± 0.8 M and ρd = 1.69 ± 0.22 g cm−3, which is in good agreement with the literature and consistent with a Neptune-like composition. For the inner planet (-e), we found a mass and density of Me = 9.0 ± 0.5 M and ρe = 8.1 ± 0.5 g cm−3, suggesting an Earth-like composition close to other ultra-hot planets at similar irradiation levels. Though this result is in agreement with previous RV plus TTV studies, it is not in agreement with the most recent RV analysis (at 2.8σ), which yielded a lower density compatible with a pure silicate composition. This discrepancy highlights the still unresolved issue of suspected systematic offsets between RV and TTV measurements. In this paper, we also significantly improve the orbital ephemerides of all transiting planets, which will be crucial for any future follow-up.

Organisation(en)
Institut für Astrophysik
Externe Organisation(en)
INAF - Osservatorio Astronomico di Padova, Università degli Studi di Padova, INAF-Osservatorio Astrofisico di Catania, Universität Genf, Universität Bern, Aix-Marseille Université, Universidade do Porto, University of St. Andrews, Université de Liège, Österreichische Akademie der Wissenschaften (ÖAW), Lund University, Instituto de Astrofísica de Canarias (IAC), Universidad de La Laguna, Spanish National Research Council (CSIC), Institut d'Estudis Espacials de Catalunya (IEEC), Admatis, European Space Astronomy Centre (ESA), Université Grenoble-Alpes, Stockholm University, Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Université de Paris, INAF-Osservatorio Astrofisico di Torino, Leiden University, Chalmers University of Technology, Università degli Studi di Torino, European Space Research & Technology Centre (ESA/ESTEC), MTA Társadalomtudományi Kutatóközpont, Eötvös Loránd University Budapest, Université de recherche Paris Sciences et Lettres, Université Paris VI - Pierre-et-Marie-Curie, Instituto de Astrofísica de Andalucía, University of Chicago, Keele University, University of Warwick, Eidgenössische Technische Hochschule Zürich, University of Cambridge, Technische Universität Berlin, Freie Universität Berlin (FU)
Journal
Astronomy and Astrophysics
Band
673
Anzahl der Seiten
17
ISSN
0004-6361
DOI
https://doi.org/10.1051/0004-6361/202245486
Publikationsdatum
05-2023
Peer-reviewed
Ja
ÖFOS 2012
103003 Astronomie, 103004 Astrophysik, 103038 Weltraumforschung
Schlagwörter
ASJC Scopus Sachgebiete
Astronomy and Astrophysics, Space and Planetary Science
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/d0b4fe6b-a900-47a5-8e1d-cb52bf4d4533