TOI-1055 b: Neptunian planet characterised with HARPS, TESS, and CHEOPS
Artikel i vetenskaplig tidskrift, 2023
Context. TOI-1055 is a Sun-like star known to host a transiting Neptune-sized planet on a 17.5-day orbit (TOI-1055 b). Radial velocity (RV) analyses carried out by two independent groups using nearly the same set of HARPS spectra have provided measurements of planetary masses that differ by ∼2σ. Aims. Our aim in this work is to solve the inconsistency in the published planetary masses by significantly extending the set of HARPS RV measurements and employing a new analysis tool that is able to account and correct for stellar activity. Our further aim was to improve the precision on measurements of the planetary radius by observing two transits of the planet with the CHEOPS space telescope. Methods. We fit a skew normal function to each cross correlation function extracted from the HARPS spectra to obtain RV measurements and hyperparameters to be used for the detrending. We evaluated the correlation changes of the hyperparameters along the RV time series using the breakpoint technique. We performed a joint photometric and RV analysis using a Markov chain Monte Carlo scheme to simultaneously detrend the light curves and the RV time series. Results. We firmly detected the Keplerian signal of TOI-1055 b, deriving a planetary mass of Mb = 20.4-2.5+2.6 MO (∼12%). This value is in agreement with one of the two estimates in the literature, but it is significantly more precise. Thanks to the TESS transit light curves combined with exquisite CHEOPS photometry, we also derived a planetary radius of Rb = 3.490-0.064+0.070 RO (∼1.9%). Our mass and radius measurements imply a mean density of ρb = 2.65-0.35+0.37 g cm-3 (∼14%). We further inferred the planetary structure and found that TOI-1055 b is very likely to host a substantial gas envelope with a mass of 0.41-0.20+0.34 MO and a thickness of 1.05-0.29+0.30 RO. Conclusions. Our RV extraction combined with the breakpoint technique has played a key role in the optimal removal of stellar activity from the HARPS time series, enabling us to solve the tension in the planetary mass values published so far for TOI-1055 b.
Planets and satellites: fundamental parameters
Techniques: radial velocities
Techniques: photometric
Stars: fundamental parameters
Författare
A. Bonfanti
Institut fur Weltraumforschung
D. Gandolfi
Universita degli Studi di Torino
J. A. Egger
Universität Bern
L. Fossati
Institut fur Weltraumforschung
J. Cabrera
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
A. Krenn
Institut fur Weltraumforschung
Y. Alibert
Universität Bern
W. Benz
Universität Bern
N. Billot
Université de Genève
H.-G. Florén
Stockholms universitet
M. Lendl
Université de Genève
V. Adibekyan
Universidade do Porto
S. Salmon
Université de Genève
N. C. Santos
Universidade do Porto
S. G. Sousa
Universidade do Porto
T. G. Wilson
University of St Andrews
O. Barragán
University of Oxford
A. Collier Cameron
University of St Andrews
L. Delrez
Universite de Liège
M. Esposito
Thüringer Landessternwarte Tautenburg
E. Goffo
Universita degli Studi di Torino
Thüringer Landessternwarte Tautenburg
H. L.M. Osborne
University College London (UCL)
H. P. Osborn
Universität Bern
Massachusetts Institute of Technology (MIT)
L. M. Serrano
Universita degli Studi di Torino
Vincent Van Eylen
University College London (UCL)
Javier Alarcon
European Southern Observatory Santiago
R. Alonso
Universidad de la Laguna
Instituto de Astrofísica de Canarias
G. Anglada
Consejo Superior de Investigaciones Científicas (CSIC)
Centre Tecnològic de Telecomunicacions de Catalunya (CTTC)
T. Bárczy
Admatis
D. Barrado Navascues
Centro de Astrobiologia (CAB)
S. C.C. Barros
Universidade do Porto
W. Baumjohann
Institut fur Weltraumforschung
M. Beck
Université de Genève
T. Beck
Universität Bern
Megan Bedell
Flatiron Institute
X. Bonfils
Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
L. Borsato
Istituto nazionale di astrofisica (INAF)
A. Brandeker
Stockholms universitet
C. Broeg
Universität Bern
S. Charnoz
Institut de Physique du Globe de Paris
C. Corral Van Damme
Europeiska rymdorganisationen (ESA)
Szilard Csizmadia
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
P. E. Cubillos
Institut fur Weltraumforschung
Istituto nazionale di astrofisica (INAF)
M. B. Davies
Lunds universitet
M. Deleuil
Laboratoire d'Astrophysique de Marseille
O. Demangeon
Universidade do Porto
B.O. Demory
Universität Bern
D. Ehrenreich
Université de Genève
Anders Erikson
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
A. Fortier
Universität Bern
Malcolm Fridlund
Universiteit Leiden
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
Michaël Gillon
Universite de Liège
M. Gudel
Universität Wien
S. Hoyer
Laboratoire d'Astrophysique de Marseille
K. Isaak
Europeiska rymdorganisationen (ESA)
F. Kerschbaum
Universität Wien
L.L. Kiss
Magyar Tudomanyos Akademia
Eötvös Loránd University (ELTE)
J. Laskar
Observatoire de Paris
A. L. des Etangs
Institut d 'Astrophysique de Paris
D. Lorenzo-Oliveira
Universidade de Sao Paulo (USP)
Laboratorio Nacional de Astrofisica, Itajuba
C. Lovis
Université de Genève
D. Magrin
Istituto nazionale di astrofisica (INAF)
L. Marafatto
Istituto nazionale di astrofisica (INAF)
P. Maxted
Keele University
J. Meléndez
Universidade de Sao Paulo (USP)
C. Mordasini
Universität Bern
Valerio Nascimbeni
Istituto nazionale di astrofisica (INAF)
G. Olofsson
Stockholms universitet
R. Ottensamer
Universität Wien
I. Pagano
Istituto nazionale di astrofisica (INAF)
E. Palle
Instituto de Astrofísica de Canarias
G. Peter
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
D. Piazza
Universität Bern
Giampaolo P. Piotto
Università di Padova
Istituto nazionale di astrofisica (INAF)
D. Pollacco
The University of Warwick
D. Queloz
Eidgenössische Technische Hochschule Zürich (ETH)
University of Cambridge
Roberto Ragazzoni
Università di Padova
Istituto nazionale di astrofisica (INAF)
N. Rando
Europeiska rymdorganisationen (ESA)
H. Rauer
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
Freie Universität Berlin
Technische Universität Berlin
I. Ribas
Consejo Superior de Investigaciones Científicas (CSIC)
Centre Tecnològic de Telecomunicacions de Catalunya (CTTC)
Gaetano Scandariato
Istituto nazionale di astrofisica (INAF)
D. Segransan
Université de Genève
A.E. Simon
Universität Bern
A. M.S. Smith
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
Manfred B. Steller
Institut fur Weltraumforschung
Gy M. Szabó
Eötvös Loránd University (ELTE)
N. Thomas
Universität Bern
S. Udry
Université de Genève
B. Ulmer
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
V. Van Grootel
Universite de Liège
J. Venturini
Université de Genève
N. A. Walton
University of Cambridge
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 671 L8Ämneskategorier (SSIF 2011)
Medicinsk laboratorie- och mätteknik
Analytisk kemi
Astronomi, astrofysik och kosmologi
DOI
10.1051/0004-6361/202245607