Uncovering the true periods of the young sub-Neptunes orbiting TOI-2076

Autor(en)

H. P. Osborn, A. Bonfanti, D. Gandolfi, C. Hedges, A. Leleu, A. Fortier, D. Futyan, P. Gutermann, P. F.L. Maxted, L. Borsato, K. A. Collins, J. Gomes Da Silva, Y. Gomez Maqueo Chew, M. J. Hooton, M. Lendl, H. Parviainen, S. Salmon, N. Schanche, L. M. Serrano, S. G. Sousa, A. Tuson, S. Ulmer-Moll, V. Van Grootel, R. D. Wells, T. G. Wilson, Y. Alibert, R. Alonso, G. Anglada, J. Asquier, D. Barrado Y Navascues, W. Baumjohann, T. Beck, W. Benz, F. Biondi, X. Bonfils, F. Bouchy, A. Brandeker, C. Broeg, T. Barczy, S. C.C. Barros, J. Cabrera, S. Charnoz, A. Collier Cameron, S. Csizmadia, M. B. Davies, M. Deleuil, L. Delrez, B. O. Demory, D. Ehrenreich, A. Erikson, L. Fossati, M. Fridlund, M. Gillon, M. A. Gomez-Munoz, M. Gudel, K. Heng, S. Hoyer, K. G. Isaak, L. Kiss, J. Laskar, A. Lecavelier Des Etangs, C. Lovis, D. Magrin, L. Malavolta, J. McCormac, V. Nascimbeni, G. Olofsson, R. Ottensamer, I. Pagano, E. Palle, G. Peter, D. Piazza, G. Piotto, D. Pollacco, D. Queloz, R. Ragazzoni, N. Rando, H. Rauer, C. Reimers, I. Ribas, O. D.S. Demangeon, A. M.S. Smith, L. Sabin, N. Santos, G. Scandariato, U. Schroffenegger, R. P. Schwarz, A. Shporer, A. E. Simon, M. Steller, G. M. Szabo, D. Segransan, N. Thomas, S. Udry, I. Walter, N. Walton

Abstrakt

Context. TOI-2076 is a transiting three-planet system of sub-Neptunes orbiting a bright (G = 8.9 mag), young (340 ±80 Myr) K-type star. Although a validated planetary system, the orbits of the two outer planets were unconstrained as only two non-consecutive transits were seen in TESS photometry. This left 11 and 7 possible period aliases for each. Aims. To reveal the true orbits of these two long-period planets, precise photometry targeted on the highest-probability period aliases is required. Long-term monitoring of transits in multi-planet systems can also help constrain planetary masses through TTV measurements. Methods. We used the MonoTools package to determine which aliases to follow, and then performed space-based and ground-based photometric follow-up of TOI-2076 c and d with CHEOPS, SAINT-EX, and LCO telescopes. Results. CHEOPS observations revealed a clear detection for TOI-2076 c at P = 21.01538+0.00084 -0.00074 d, and allowed us to rule out three of the most likely period aliases for TOI-2076 d. Ground-based photometry further enabled us to rule out remaining aliases and confirm the P = 35.12537 ±0.00067 d alias. These observations also improved the radius precision of all three sub-Neptunes to 2.518 ±0.036, 3.497 ±0.043, and 3.232 ±0.063 R⊕;. Our observations also revealed a clear anti-correlated TTV signal between planets b and c likely caused by their proximity to the 2:1 resonance, while planets c and d appear close to a 5:3 period commensurability, although model degeneracy meant we were unable to retrieve robust TTV masses. Their inflated radii, likely due to extended H-He atmospheres, combined with low insolation makes all three planets excellent candidates for future comparative transmission spectroscopy with JWST.

Organisation(en)

Institut für Astrophysik

Externe Organisation(en)

Universität Bern, Massachusetts Institute of Technology, Österreichische Akademie der Wissenschaften (ÖAW), Università degli Studi di Torino, Bay Area Environmental Research Institute, National Aeronautics & Space Administration (NASA), Universität Genf, Aix-Marseille Université, National Institute for Earth Sciences & Astronomy (INSU-CNRS), Keele University, INAF - Osservatorio Astronomico di Padova, Harvard-Smithsonian Center for Astrophysics, Universidade do Porto, Universidad Nacional Autonoma de Mexico, Instituto de Astrofísica de Canarias (IAC), Universidad de La Laguna, University of Cambridge, Université de Liège, University of St. Andrews, Spanish National Research Council (CSIC), Universitat Autònoma de Barcelona , Institut d'Estudis Espacials de Catalunya (IEEC), European Space Research & Technology Centre (ESA/ESTEC), European Space Astronomy Centre (ESA), Max-Planck-Institut für extraterrestrische Physik, Université Grenoble-Alpes, Stockholm University, Admatis, Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Université de Paris, Lund University, Leiden University, Chalmers University of Technology, University of Warwick, MTA Társadalomtudományi Kutatóközpont, Eötvös Loránd University Budapest, Université de recherche Paris Sciences et Lettres, Université Paris VI - Pierre-et-Marie-Curie, Università degli Studi di Padova, INAF-Osservatorio Astrofisico di Catania, Technische Universität Berlin, Patashnick Voorheesville Observatory

Journal

Astronomy and Astrophysics

Band

664

Anzahl der Seiten

17

ISSN

0004-6361

DOI

https://doi.org/10.1051/0004-6361/202243065

Publikationsdatum

08-2022

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/fdf3aad1-4ed9-46c1-90b8-5abc5652f929