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.

Techniques: radial velocities

Planets and satellites: fundamental parameters

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

Thüringer Landessternwarte Tautenburg

Universita degli Studi di Torino

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

Instituto de Astrofísica de Canarias

Universidad de la Laguna

G. Anglada

Centre Tecnològic de Telecomunicacions de Catalunya (CTTC)

Consejo Superior de Investigaciones Científicas (CSIC)

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

European Space Research and Technology Centre (ESA ESTEC)

Szilard Csizmadia

Deutsches Zentrums für Luft- und Raumfahrt (DLR)

P. E. Cubillos

Istituto nazionale di astrofisica (INAF)

Institut fur Weltraumforschung

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

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik

Universiteit Leiden

Michaël Gillon

Universite de Liège

M. Gudel

Universität Wien

S. Hoyer

Laboratoire d'Astrophysique de Marseille

K. Isaak

European Space Research and Technology Centre (ESA ESTEC)

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

Laboratorio Nacional de Astrofisica, Itajuba

Universidade de Sao Paulo (USP)

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

Istituto nazionale di astrofisica (INAF)

Università di Padova

N. Rando

European Space Research and Technology Centre (ESA ESTEC)

H. Rauer

Technische Universität Berlin

Freie Universität Berlin

Deutsches Zentrums für Luft- und Raumfahrt (DLR)

I. Ribas

Centre Tecnològic de Telecomunicacions de Catalunya (CTTC)

Consejo Superior de Investigaciones Científicas (CSIC)

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 L8

Ämneskategorier (SSIF 2011)

Medicinsk laboratorie- och mätteknik

Analytisk kemi

Astronomi, astrofysik och kosmologi

DOI

10.1051/0004-6361/202245607

Mer information

Senast uppdaterat

2025-03-09