Uncovering the true periods of the young sub-Neptunes orbiting TOI-2076
Journal article, 2022
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(-0.00074)(+0.00084) 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-circle plus. 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.
stars: individual: TOI-2076
techniques: photometric
planets and satellites: detection
Author
H. P. Osborn
Massachusetts Institute of Technology (MIT)
University of Bern
A. Bonfanti
Austrian Academy of Sciences
D. Gandolfi
University of Turin
C. Hedges
Bay Area Environmental Research Institute (BAER)
NASA Ames Research Center
A. Leleu
University of Geneva
A. Fortier
University of Bern
D. Futyan
University of Geneva
P. Gutermann
Aix Marseille University
Institut National des Sciences de l'Univers
P. F. L. Maxted
Keele University
L. Borsato
Istituto nazionale di astrofisica (INAF)
K. A. Collins
Harvard-Smithsonian Center for Astrophysics
J. Gomes da Silva
University of Porto
Y. Gomez Maqueo Chew
Universidad Nacional Autónoma de México
M. J. Hooton
University of Bern
M. Lendl
University of Geneva
H. Parviainen
Instituto de Astrofísica de Canarias
University of La Laguna
S. Salmon
University of Geneva
N. Schanche
University of Bern
L. M. Serrano
University of Turin
S. G. Sousa
University of Porto
A. Tuson
University of Cambridge
S. Ulmer-Moll
University of Geneva
V. Van Grootel
University of Liège
R. D. Wells
University of Bern
T. G. Wilson
University of St Andrews
Y. Alibert
University of Bern
R. Alonso
Instituto de Astrofísica de Canarias
University of La Laguna
G. Anglada
Institute of Space Studies of Catalonia (IEEC)
Spanish National Research Council (CSIC)
J. Asquier
European Space Agency (ESA)
D. Barrado y Navascues
Spanish Astrobiology Center (INTA-CSIC)
W. Baumjohann
Austrian Academy of Sciences
T. Beck
University of Bern
W. Benz
University of Bern
F. Biondi
Max Planck Institute for Extraterrestrial Physics
Istituto nazionale di astrofisica (INAF)
X. Bonfils
Grenoble Alpes University
F. Bouchy
University of Geneva
A. Brandeker
Stockholm University
C. Broeg
University of Bern
T. Barczy
Admatis
S. C. C. Barros
University of Porto
J. Cabrera
German Aerospace Center (DLR)
S. Charnoz
Paris Descartes University
A. Collier Cameron
University of St Andrews
S. Csizmadia
German Aerospace Center (DLR)
M. B. Davies
Lund University
M. Deleuil
Aix Marseille University
L. Delrez
University of Liège
B-O Demory
University of Bern
D. Ehrenreich
University of Geneva
A. Erikson
German Aerospace Center (DLR)
L. Fossati
Austrian Academy of Sciences
Malcolm Fridlund
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
M. Gillon
University of Liège
M. A. Gomez-Munoz
Universidad Nacional Autónoma de México
M. Gudel
University of Vienna
K. Heng
The University of Warwick
University of Bern
S. Hoyer
Aix Marseille University
K. G. Isaak
European Space Agency (ESA)
L. Kiss
Hungarian Academy of Sciences
Eötvös Loránd University (ELTE)
J. Laskar
Sorbonne University
A. Lecavelier des Etangs
Sorbonne University
C. Lovis
University of Geneva
D. Magrin
Istituto nazionale di astrofisica (INAF)
L. Malavolta
University of Padua
Istituto nazionale di astrofisica (INAF)
J. McCormac
The University of Warwick
V Nascimbeni
Istituto nazionale di astrofisica (INAF)
G. Olofsson
Stockholm University
R. Ottensamer
University of Vienna
I Pagano
Istituto nazionale di astrofisica (INAF)
E. Palle
Instituto de Astrofísica de Canarias
University of La Laguna
G. Peter
German Aerospace Center (DLR)
D. Piazza
University of Bern
G. Piotto
University of Padua
Istituto nazionale di astrofisica (INAF)
D. Pollacco
The University of Warwick
D. Queloz
University of Cambridge
University of Geneva
R. Ragazzoni
University of Padua
Istituto nazionale di astrofisica (INAF)
N. Rando
European Space Agency (ESA)
H. Rauer
Technische Universität Berlin
German Aerospace Center (DLR)
C. Reimers
University of Vienna
I Ribas
Institute of Space Studies of Catalonia (IEEC)
Spanish National Research Council (CSIC)
O. D. S. Demangeon
University of Porto
A. M. S. Smith
German Aerospace Center (DLR)
L. Sabin
Universidad Nacional Autónoma de México
N. Santos
University of Porto
G. Scandariato
Istituto nazionale di astrofisica (INAF)
U. Schroffenegger
University of Bern
R. P. Schwarz
Patashnick Voorheesville Observatory
A. Shporer
Massachusetts Institute of Technology (MIT)
A. E. Simon
University of Bern
M. Steller
Austrian Academy of Sciences
G. M. Szabo
Eötvös Loránd University (ELTE)
D. Segransan
University of Geneva
N. Thomas
University of Bern
S. Udry
University of Geneva
I Walter
German Aerospace Center (DLR)
N. Walton
University of Cambridge
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 664 A156Subject Categories
Astronomy, Astrophysics and Cosmology
Biomedical Laboratory Science/Technology
Signal Processing
DOI
10.1051/0004-6361/202243065