TOI-1055 b: Neptunian planet characterised with HARPS, TESS, and CHEOPS

A. Bonfanti; D. Gandolfi; J.A. Egger; L. Fossati; J. Cabrera; A. Krenn; Y. Alibert; W. Benz; N. Billot; H.-G. Florén; M. Lendl; V. Adibekyan; S. Salmon; N.C. Santos; S.G. Sousa; T.G. Wilson; O. Barragán; A. Collier Cameron; L. Delrez; M. Esposito; E. Goffo; H. Osborne; H.P. Osborn; L.M. Serrano; V. Van Eylen; J. Alarcon; R. Alonso; G. Anglada; T. Bárczy; D. Barrado Navascues; S.C.C. Barros; W. Baumjohann; M. Beck; T. Beck; M. Bedell; X. Bonfils; L. Borsato; A. Brandeker; C. Broeg; S. Charnoz; C. Corral Van Damme; S. Csizmadia; P.E. Cubillos; M.B. Davies; M. Deleuil; O.D.S. Demangeon; B.-O. Demory; D. Ehrenreich; A. Erikson; A. Fortier; M. Fridlund; M. Gillon; M. Güdel; S. Hoyer; K.G. Isaak; F. Kerschbaum; L.L. Kiss; J. Laskar; A. Lecavelier Des Etangs; D. Lorenzo-Oliveira; C. Lovis; D. Magrin; L. Marafatto; P.F.L. Maxted; J. Meléndez; C. Mordasini; V. Nascimbeni; G. Olofsson; R. Ottensamer; I. Pagano; E. Pallé; G. Peter; D. Piazza; G. Piotto; D. Pollacco; D. Queloz; R. Ragazzoni; N. Rando; H. Rauer; I. Ribas; G. Scandariato; D. Ségransan; A.E. Simon; A.M.S. Smith; M. Steller; G.M. Szabó; N. Thomas; S. Udry; B. Ulmer; V. Van Grootel; J. Venturini; N.A. Walton

doi:10.1051/0004-6361/202245607

TOI-1055 b: Neptunian planet characterised with HARPS, TESS, and CHEOPS

A. Bonfanti^*, D. Gandolfi, J.A. Egger, L. Fossati, J. Cabrera, A. Krenn, Y. Alibert, W. Benz, N. Billot, H.-G. Florén, M. Lendl, V. Adibekyan, S. Salmon, N.C. Santos, S.G. Sousa, T.G. Wilson, O. Barragán, A. Collier Cameron, L. Delrez, M. EspositoE. Goffo, H. Osborne, H.P. Osborn, L.M. Serrano, V. Van Eylen, J. Alarcon, R. Alonso, G. Anglada, T. Bárczy, D. Barrado Navascues, S.C.C. Barros, W. Baumjohann, M. Beck, T. Beck, M. Bedell, X. Bonfils, L. Borsato, A. Brandeker, C. Broeg, S. Charnoz, C. Corral Van Damme, S. Csizmadia, P.E. Cubillos, M.B. Davies, M. Deleuil, O.D.S. Demangeon, B.-O. Demory, D. Ehrenreich, A. Erikson, A. Fortier, M. Fridlund, M. Gillon, M. Güdel, S. Hoyer, K.G. Isaak, F. Kerschbaum, L.L. Kiss, J. Laskar, A. Lecavelier Des Etangs, D. Lorenzo-Oliveira, C. Lovis, D. Magrin, L. Marafatto, P.F.L. Maxted, J. Meléndez, C. Mordasini, V. Nascimbeni, G. Olofsson, R. Ottensamer, I. Pagano, E. Pallé, G. Peter, D. Piazza, G. Piotto, D. Pollacco, D. Queloz, R. Ragazzoni, N. Rando, H. Rauer, I. Ribas, G. Scandariato, D. Ségransan, A.E. Simon, A.M.S. Smith, M. Steller, G.M. Szabó, N. Thomas, S. Udry, B. Ulmer, V. Van Grootel, J. Venturini, N.A. Walton

^*Corresponding author for this work

Research output: Contribution to journal › Letter › peer-review

Abstract

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 M_b = 20.4_-2.5^+2.6 M⊕ (∼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 R_b = 3.490_-0.064^+0.070 R⊕ (∼1.9%). Our mass and radius measurements imply a mean density of ρ_b = 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 M⊕ and a thickness of 1.05_-0.29^+0.30 R⊕.

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.

Original language	English
Article number	L8
Number of pages	13
Journal	Astronomy and Astrophysics
Volume	671
Early online date	8 Mar 2023
DOIs	https://doi.org/10.1051/0004-6361/202245607
Publication status	Published - 8 Mar 2023

Keywords

Planets and satellites: fundamental parameters
Stars: fundamental parameters
Techniques: photometric
Techniques: radial velocities

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Bonfanti_2023_AA_TOI-1055b_CC
Copyright © The Authors 2023. Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Final published version, 1.05 MBLicence: CC BY

AO2 - Professor Andrew Cameron: Project AO2 - Andrew Cameron
Cameron, A. C. (PI)
Science & Technology Facilities Council
1/04/21 → 31/03/24
Project: Standard
Astronomy at St Andrews 2018-2021: Astronomy at St Andrews 2018-2021
Jardine, M. M. (PI), Bonnell, I. A. (CoI), Cameron, A. C. (CoI), Cyganowski, C. J. (CoI), Dominik, M. (CoI), Helling, C. (CoI), Horne, K. D. (CoI), Scholz, A. (CoI), Tojeiro, R. (CoI), Weijmans, A.-M. (CoI), Wild, V. (CoI), Woitke, P. (CoI), Wood, K. (CoI) & Zhao, H. (CoI)
1/04/18 → 31/03/22
Project: Standard
Support for the PLATO Development: Support for the PLATO Development Phase 2017-2022: Planet candidate ranking and validation
Cameron, A. C. (PI)
Science & Technology Facilities Council
1/08/17 → 31/12/22
Project: Standard

TOI-1055 b A neptunian planet characterised with HARPS, TESS, and CHEOPS. (2023) (dataset)
Wilson, T. G. (Creator) & Cameron, A. C. (Creator), VizieR On-line Data Catalog, 2023
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/671/L8
Dataset

Cite this

Bonfanti, A., Gandolfi, D., Egger, J. A., Fossati, L., Cabrera, J., Krenn, A., Alibert, Y., Benz, W., Billot, N., Florén, H.-G., Lendl, M., Adibekyan, V., Salmon, S., Santos, N. C., Sousa, S. G., Wilson, T. G., Barragán, O., Collier Cameron, A., Delrez, L., ... Walton, N. A. (2023). TOI-1055 b: Neptunian planet characterised with HARPS, TESS, and CHEOPS. Astronomy and Astrophysics, 671, Article L8. https://doi.org/10.1051/0004-6361/202245607

@article{c7de341d51af435a9ccb592b044a49fc,

title = "TOI-1055 b: Neptunian planet characterised with HARPS, TESS, and CHEOPS",

abstract = "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 M⊕ (∼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 R⊕ (∼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 M⊕ and a thickness of 1.05-0.29+0.30 R⊕. 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.",

keywords = "Planets and satellites: fundamental parameters, Stars: fundamental parameters, Techniques: photometric, Techniques: radial velocities",

author = "A. Bonfanti and D. Gandolfi and J.A. Egger and L. Fossati and J. Cabrera and A. Krenn and Y. Alibert and W. Benz and N. Billot and H.-G. Flor{\'e}n and M. Lendl and V. Adibekyan and S. Salmon and N.C. Santos and S.G. Sousa and T.G. Wilson and O. Barrag{\'a}n and {Collier Cameron}, A. and L. Delrez and M. Esposito and E. Goffo and H. Osborne and H.P. Osborn and L.M. Serrano and {Van Eylen}, V. and J. Alarcon and R. Alonso and G. Anglada and T. B{\'a}rczy and {Barrado Navascues}, D. and S.C.C. Barros and W. Baumjohann and M. Beck and T. Beck and M. Bedell and X. Bonfils and L. Borsato and A. Brandeker and C. Broeg and S. Charnoz and {Corral Van Damme}, C. and S. Csizmadia and P.E. Cubillos and M.B. Davies and M. Deleuil and O.D.S. Demangeon and B.-O. Demory and D. Ehrenreich and A. Erikson and A. Fortier and M. Fridlund and M. Gillon and M. G{\"u}del and S. Hoyer and K.G. Isaak and F. Kerschbaum and L.L. Kiss and J. Laskar and {Lecavelier Des Etangs}, A. and D. Lorenzo-Oliveira and C. Lovis and D. Magrin and L. Marafatto and P.F.L. Maxted and J. Mel{\'e}ndez and C. Mordasini and V. Nascimbeni and G. Olofsson and R. Ottensamer and I. Pagano and E. Pall{\'e} and G. Peter and D. Piazza and G. Piotto and D. Pollacco and D. Queloz and R. Ragazzoni and N. Rando and H. Rauer and I. Ribas and G. Scandariato and D. S{\'e}gransan and A.E. Simon and A.M.S. Smith and M. Steller and G.M. Szab{\'o} and N. Thomas and S. Udry and B. Ulmer and {Van Grootel}, V. and J. Venturini and N.A. Walton",

note = "Funding: DG gratefully acknowledges financial support from the CRT foundation under Grant No. 2018.2323 “Gaseousor rocky? Unveiling the nature of small worlds”. JAEg and YAl acknowledge the support of the Swiss National Fund under grant 200020_172746. ML acknowledges support of the Swiss National Science Foundation under grant number PCEFP2_194576. SS have received funding from the European Research Council (ERC) under the European Union{\textquoteright}s Horizon 2020 research and innovation program (grant agreement No 833925, project STAREX). S.G.S. acknowledges support from FCT through FCT contract nr. CEECIND/00826/2018 and POPH/FSE (EC). TWi and ACCa acknowledge support from STFC consolidated grant numbers ST/R000824/1 and ST/V000861/1, and UKSA grant number ST/R003203/1. The Belgian participation to CHEOPS has been supported by the Belgian Federal Science Policy Office (BELSPO) in the framework of the PRODEX Program, and by the University of Li{\`e}ge through an ARC grant for Concerted Research Actions financed by the Wallonia-Brussels Federation. L.D. is an F.R.S.-FNRS Postdoctoral Researcher. This work has been carried out within the framework of the NCCR PlanetS supported by the Swiss National Science Foundation under grants 51NF40_182901 and 51NF40_205606. LMS gratefully acknowledges financial support from the CRT foundation under Grant No. 2018.2323 {\textquoteleft}Gaseous or rocky? Unveiling the nature of small worlds{\textquoteright}. We acknowledge support from the Spanish Ministry of Science and Innovation and the European Regional Development Fund through grants ESP2016-80435-C2-1-R, ESP2016-80435-C2-2-R, PGC2018-098153-B-C33, PGC2018-098153-B-C31, ESP2017-87676-C5-1-R, MDM-2017-0737 Unidad de Excelencia Maria de Maeztu-Centro de Astrobiolog{\'i}a (INTA-CSIC), as well as the support of the Generalitat de Catalunya/CERCA programme. The MOC activities have been supported by the ESA contract No. 4000124370. S.C.C.B. acknowledges support from FCT through FCT contracts nr. IF/01312/2014/CP1215/CT0004. XB, SC, DG, MF and JL acknowledge their role as ESA-appointed CHEOPS science team members. LBo, VNa, IPa, GPi, RRa, and GSc acknowledge support from CHEOPS ASI-INAF agreement n. 2019-29-HH.0. ABr was supported by the SNSA. This project was supported by the CNES. This work was supported by FCT – Funda{\c c}{\~a}o para a Ci{\^e}ncia e a Tecnologia through national funds and by FEDER through COMPETE2020 – Programa Operacional Competitividade e Internacionalizac{\~a}o by these grants: UID/FIS/04434/2019, UIDB/04434/2020, UIDP/04434/2020, PTDC/FIS-AST/32113/2017 & POCI-01-0145-FEDER- 032113, PTDC/FIS-AST/28953/2017 & POCI-01-0145-FEDER-028953, PTDC/FIS-AST/28987/2017 & POCI-01-0145-FEDER-028987, O.D.S.D. is supported in the form of work contract (DL 57/2016/CP1364/CT0004) funded by national funds through FCT. B.-O. D. acknowledges support from the Swiss State Secretariat for Education, Research and Innovation (SERI) under contract number MB22.00046. This project has received funding from the European Research Council (ERC) under the European Union{\textquoteright}s Horizon 2020 research and innovation programme (project F OUR A CES . grant agreement No 724427). It has also been carried out in the frame of the National Centre for Competence in Research PlanetS supported by the Swiss National Science Foundation (SNSF). DE acknowledges financial support from the Swiss National Science Foundation for project 200021_200726. MF and CMP gratefully acknowledge the support of the Swedish National Space Agency (DNR 65/19, 174/18). M.G. is an F.R.S.-FNRS Senior Research Associate. SH gratefully acknowledges CNES funding through the grant 837319. KGI is the ESA CHEOPS Project Scientist and is responsible for the ESA CHEOPS Guest Observers Programme. She does not participate in, or contribute to, the definition of the Guaranteed Time Programme of the CHEOPS mission through which observations described in this paper have been taken, nor to any aspect of target selection for the programme. This work was granted access to the HPC resources of MesoPSL financed by the Region Ile de France and the project Equip@Meso (reference ANR-10-EQPX-29-01) of the programme Investissements d{\textquoteright}Avenir supervised by the Agence Nationale pour la Recherche. PM acknowledges support from STFC research grant number ST/M001040/1. This work was also partially supported by a grant from the Simons Foundation (PI Queloz, grant number 327127). IRI acknowledges support from the Spanish Ministry of Science and Innovation and the European Regional Development Fund through grant PGC2018-098153-B- C33, as well as the support of the Generalitat de Catalunya/CERCA programme. GyMSz acknowledges the support of the Hungarian National Research, Development and Innovation Office (NKFIH) grant K-125015, a a PRODEX Experiment Agreement No. 4000137122, the Lend{\"u}let LP2018-7/2021 grant of the Hungarian Academy of Science and the support of the city of Szombathely. V.V.G. is an F.R.S-FNRS Research Associate. NAW acknowledges UKSA grant ST/R004838/1. Funding text 2: Acknowledgements. CHEOPS is an ESA mission in partnership with Switzerland with important contributions to the payload and the ground segment from Austria, Belgium, France, Germany, Hungary, Italy, Portugal, Spain, Sweden, and the United Kingdom. The CHEOPS Consortium would like to gratefully acknowledge the support received by all the agencies, offices, universities, and industries involved. Their flexibility and willingness to explore new approaches were essential to the success of this mission. We thank the anonymous referee, whose valuable comments have improved the quality of the manuscript. DG gratefully acknowledges financial support from the CRT foundation under Grant No. 2018.2323 {"}Gaseousor rocky? Unveiling the nature of small worlds{"}. JAEg and YAl acknowledge the support of the Swiss National Fund under grant 200020_172746. ML acknowledges support of the Swiss National Science Foundation under grant number PCEFP2_194576. SS have received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No 833925, project STAREX). S.G.S. acknowledges support from FCT through FCT contract nr. CEECIND/00826/2018 and POPH/FSE (EC). TWi and ACCa acknowledge support from STFC consolidated grant numbers ST/R000824/1 and ST/V000861/1, and UKSA grant number ST/R003203/1. The Belgian participation to CHEOPS has been supported by the Belgian Federal Science Policy Office (BELSPO) in the framework of the PRODEX Program, and by the University of Li{\`e}ge through an ARC grant for Concerted Research Actions financed by the Wallonia-Brussels Federation. L.D. is an F.R.S.-FNRS Postdoctoral Researcher. This work has been carried out within the framework of the NCCR PlanetS supported by the Swiss National Science Foundation under grants 51NF40_182901 and 51NF40_205606. LMS gratefully acknowledges financial support from the CRT foundation under Grant No. 2018.2323 'Gaseous or rocky? Unveiling the nature of small worlds'. We acknowledge support from the Spanish Ministry of Science and Innovation and the European Regional Development Fund through grants ESP2016-80435-C2-1-R, ESP2016-80435-C2-2-R, PGC2018-098153-B-C33, PGC2018-098153-B-C31, ESP2017-87676-C5-1-R, MDM-2017-0737 Unidad de Excelencia Maria de Maeztu-Centro de Astrobiolog{\'i}a (INTA-CSIC), as well as the support of the Generalitat de Catalunya/CERCA programme. The MOC activities have been supported by the ESA contract No. 4000124370. S.C.C.B. acknowledges support from FCT through FCT contracts nr. IF/01312/2014/CP1215/CT0004. XB, SC, DG, MF and JL acknowledge their role as ESA-appointed CHEOPS science team members. LBo, VNa, IPa, GPi, RRa, and GSc acknowledge support from CHEOPS ASI-INAF agreement n. 2019-29-HH.0. ABr was supported by the SNSA. This project was supported by the CNES. This work was supported by FCT - Funda{\c c}{\~a}o para a Ci{\^e}ncia e a Tecnologia through national funds and by FEDER through COMPETE2020 - Programa Operacional Competitividade e Internacionalizac{\~a}o by these grants: UID/FIS/04434/2019, UIDB/04434/2020, UIDP/04434/2020, PTDC/FIS-AST/32113/2017 & POCI-01-0145-FEDER- 032113, PTDC/FIS-AST/28953/2017 & POCI-01-0145-FEDER-028953, PTDC/FIS-AST/28987/2017 & POCI-01-0145-FEDER-028987, O.D.S.D. is supported in the form of work contract (DL 57/2016/CP1364/CT0004) funded by national funds through FCT. B.-O. D. acknowledges support from the Swiss State Secretariat for Education, Research and Innovation (SERI) under contract number MB22.00046. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (project Four Aces. grant agreement No 724427). It has also been carried out in the frame of the National Centre for Competence in Research PlanetS supported by the Swiss National Science Foundation (SNSF). DE acknowledges financial support from the Swiss National Science Foundation for project 200021_200726. MF and CMP gratefully acknowledge the support of the Swedish National Space Agency (DNR 65/19, 174/18). M.G. is an F.R.S.-FNRS Senior Research Associate. SH gratefully acknowledges CNES funding through the grant 837319. KGI is the ESA CHEOPS Project Scientist and is responsible for the ESA CHEOPS Guest Observers Programme. She does not participate in, or contribute to, the definition of the Guaranteed Time Programme of the CHEOPS mission through which observations described in this paper have been taken, nor to any aspect of target selection for the programme. This work was granted access to the HPC resources of MesoPSL financed by the Region Ile de France and the project Equip@Meso (reference ANR-10-EQPX-29-01) of the programme Investissements d'Avenir supervised by the Agence Nationale pour la Recherche. PM acknowledges support from STFC research grant number ST/M001040/1. This work was also partially supported by a grant from the Simons Foundation (PI Queloz, grant number 327127). IRI acknowledges support from the Spanish Ministry of Science and Innovation and the European Regional Development Fund through grant PGC2018-098153-B- C33, as well as the support of the Generalitat de Catalunya/CERCA programme. GyMSz acknowledges the support of the Hungarian National Research, Development and Innovation Office (NKFIH) grant K-125015, a a PRODEX Experiment Agreement No. 4000137122, the Lend{\"u}let LP2018-7/2021 grant of the Hungarian Academy of Science and the support of the city of Szombathely. V.V.G. is an F.R.S-FNRS Research Associate. NAW acknowledges UKSA grant ST/R004838/1.",

year = "2023",

month = mar,

day = "8",

doi = "10.1051/0004-6361/202245607",

language = "English",

volume = "671",

journal = "Astronomy and Astrophysics",

issn = "0004-6361",

publisher = "EDP SCIENCES S A",

}

Bonfanti, A, Gandolfi, D, Egger, JA, Fossati, L, Cabrera, J, Krenn, A, Alibert, Y, Benz, W, Billot, N, Florén, H-G, Lendl, M, Adibekyan, V, Salmon, S, Santos, NC, Sousa, SG, Wilson, TG, Barragán, O, Collier Cameron, A, Delrez, L, Esposito, M, Goffo, E, Osborne, H, Osborn, HP, Serrano, LM, Van Eylen, V, Alarcon, J, Alonso, R, Anglada, G, Bárczy, T, Barrado Navascues, D, Barros, SCC, Baumjohann, W, Beck, M, Beck, T, Bedell, M, Bonfils, X, Borsato, L, Brandeker, A, Broeg, C, Charnoz, S, Corral Van Damme, C, Csizmadia, S, Cubillos, PE, Davies, MB, Deleuil, M, Demangeon, ODS, Demory, B-O, Ehrenreich, D, Erikson, A, Fortier, A, Fridlund, M, Gillon, M, Güdel, M, Hoyer, S, Isaak, KG, Kerschbaum, F, Kiss, LL, Laskar, J, Lecavelier Des Etangs, A, Lorenzo-Oliveira, D, Lovis, C, Magrin, D, Marafatto, L, Maxted, PFL, Meléndez, J, Mordasini, C, Nascimbeni, V, Olofsson, G, Ottensamer, R, Pagano, I, Pallé, E, Peter, G, Piazza, D, Piotto, G, Pollacco, D, Queloz, D, Ragazzoni, R, Rando, N, Rauer, H, Ribas, I, Scandariato, G, Ségransan, D, Simon, AE, Smith, AMS, Steller, M, Szabó, GM, Thomas, N, Udry, S, Ulmer, B, Van Grootel, V, Venturini, J & Walton, NA 2023, 'TOI-1055 b: Neptunian planet characterised with HARPS, TESS, and CHEOPS', Astronomy and Astrophysics, vol. 671, L8. https://doi.org/10.1051/0004-6361/202245607

TY - JOUR

T1 - TOI-1055 b

T2 - Neptunian planet characterised with HARPS, TESS, and CHEOPS

AU - Bonfanti, A.

AU - Gandolfi, D.

AU - Egger, J.A.

AU - Fossati, L.

AU - Cabrera, J.

AU - Krenn, A.

AU - Alibert, Y.

AU - Benz, W.

AU - Billot, N.

AU - Florén, H.-G.

AU - Lendl, M.

AU - Adibekyan, V.

AU - Salmon, S.

AU - Santos, N.C.

AU - Sousa, S.G.

AU - Wilson, T.G.

AU - Barragán, O.

AU - Collier Cameron, A.

AU - Delrez, L.

AU - Esposito, M.

AU - Goffo, E.

AU - Osborne, H.

AU - Osborn, H.P.

AU - Serrano, L.M.

AU - Van Eylen, V.

AU - Alarcon, J.

AU - Alonso, R.

AU - Anglada, G.

AU - Bárczy, T.

AU - Barrado Navascues, D.

AU - Barros, S.C.C.

AU - Baumjohann, W.

AU - Beck, M.

AU - Beck, T.

AU - Bedell, M.

AU - Bonfils, X.

AU - Borsato, L.

AU - Brandeker, A.

AU - Broeg, C.

AU - Charnoz, S.

AU - Corral Van Damme, C.

AU - Csizmadia, S.

AU - Cubillos, P.E.

AU - Davies, M.B.

AU - Deleuil, M.

AU - Demangeon, O.D.S.

AU - Demory, B.-O.

AU - Ehrenreich, D.

AU - Erikson, A.

AU - Fortier, A.

AU - Fridlund, M.

AU - Gillon, M.

AU - Güdel, M.

AU - Hoyer, S.

AU - Isaak, K.G.

AU - Kerschbaum, F.

AU - Kiss, L.L.

AU - Laskar, J.

AU - Lecavelier Des Etangs, A.

AU - Lorenzo-Oliveira, D.

AU - Lovis, C.

AU - Magrin, D.

AU - Marafatto, L.

AU - Maxted, P.F.L.

AU - Meléndez, J.

AU - Mordasini, C.

AU - Nascimbeni, V.

AU - Olofsson, G.

AU - Ottensamer, R.

AU - Pagano, I.

AU - Pallé, E.

AU - Peter, G.

AU - Piazza, D.

AU - Piotto, G.

AU - Pollacco, D.

AU - Queloz, D.

AU - Ragazzoni, R.

AU - Rando, N.

AU - Rauer, H.

AU - Ribas, I.

AU - Scandariato, G.

AU - Ségransan, D.

AU - Simon, A.E.

AU - Smith, A.M.S.

AU - Steller, M.

AU - Szabó, G.M.

AU - Thomas, N.

AU - Udry, S.

AU - Ulmer, B.

AU - Van Grootel, V.

AU - Venturini, J.

AU - Walton, N.A.

N1 - Funding: DG gratefully acknowledges financial support from the CRT foundation under Grant No. 2018.2323 “Gaseousor rocky? Unveiling the nature of small worlds”. JAEg and YAl acknowledge the support of the Swiss National Fund under grant 200020_172746. ML acknowledges support of the Swiss National Science Foundation under grant number PCEFP2_194576. SS have received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No 833925, project STAREX). S.G.S. acknowledges support from FCT through FCT contract nr. CEECIND/00826/2018 and POPH/FSE (EC). TWi and ACCa acknowledge support from STFC consolidated grant numbers ST/R000824/1 and ST/V000861/1, and UKSA grant number ST/R003203/1. The Belgian participation to CHEOPS has been supported by the Belgian Federal Science Policy Office (BELSPO) in the framework of the PRODEX Program, and by the University of Liège through an ARC grant for Concerted Research Actions financed by the Wallonia-Brussels Federation. L.D. is an F.R.S.-FNRS Postdoctoral Researcher. This work has been carried out within the framework of the NCCR PlanetS supported by the Swiss National Science Foundation under grants 51NF40_182901 and 51NF40_205606. LMS gratefully acknowledges financial support from the CRT foundation under Grant No. 2018.2323 ‘Gaseous or rocky? Unveiling the nature of small worlds’. We acknowledge support from the Spanish Ministry of Science and Innovation and the European Regional Development Fund through grants ESP2016-80435-C2-1-R, ESP2016-80435-C2-2-R, PGC2018-098153-B-C33, PGC2018-098153-B-C31, ESP2017-87676-C5-1-R, MDM-2017-0737 Unidad de Excelencia Maria de Maeztu-Centro de Astrobiología (INTA-CSIC), as well as the support of the Generalitat de Catalunya/CERCA programme. The MOC activities have been supported by the ESA contract No. 4000124370. S.C.C.B. acknowledges support from FCT through FCT contracts nr. IF/01312/2014/CP1215/CT0004. XB, SC, DG, MF and JL acknowledge their role as ESA-appointed CHEOPS science team members. LBo, VNa, IPa, GPi, RRa, and GSc acknowledge support from CHEOPS ASI-INAF agreement n. 2019-29-HH.0. ABr was supported by the SNSA. This project was supported by the CNES. This work was supported by FCT – Fundação para a Ciência e a Tecnologia through national funds and by FEDER through COMPETE2020 – Programa Operacional Competitividade e Internacionalizacão by these grants: UID/FIS/04434/2019, UIDB/04434/2020, UIDP/04434/2020, PTDC/FIS-AST/32113/2017 & POCI-01-0145-FEDER- 032113, PTDC/FIS-AST/28953/2017 & POCI-01-0145-FEDER-028953, PTDC/FIS-AST/28987/2017 & POCI-01-0145-FEDER-028987, O.D.S.D. is supported in the form of work contract (DL 57/2016/CP1364/CT0004) funded by national funds through FCT. B.-O. D. acknowledges support from the Swiss State Secretariat for Education, Research and Innovation (SERI) under contract number MB22.00046. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (project F OUR A CES . grant agreement No 724427). It has also been carried out in the frame of the National Centre for Competence in Research PlanetS supported by the Swiss National Science Foundation (SNSF). DE acknowledges financial support from the Swiss National Science Foundation for project 200021_200726. MF and CMP gratefully acknowledge the support of the Swedish National Space Agency (DNR 65/19, 174/18). M.G. is an F.R.S.-FNRS Senior Research Associate. SH gratefully acknowledges CNES funding through the grant 837319. KGI is the ESA CHEOPS Project Scientist and is responsible for the ESA CHEOPS Guest Observers Programme. She does not participate in, or contribute to, the definition of the Guaranteed Time Programme of the CHEOPS mission through which observations described in this paper have been taken, nor to any aspect of target selection for the programme. This work was granted access to the HPC resources of MesoPSL financed by the Region Ile de France and the project Equip@Meso (reference ANR-10-EQPX-29-01) of the programme Investissements d’Avenir supervised by the Agence Nationale pour la Recherche. PM acknowledges support from STFC research grant number ST/M001040/1. This work was also partially supported by a grant from the Simons Foundation (PI Queloz, grant number 327127). IRI acknowledges support from the Spanish Ministry of Science and Innovation and the European Regional Development Fund through grant PGC2018-098153-B- C33, as well as the support of the Generalitat de Catalunya/CERCA programme. GyMSz acknowledges the support of the Hungarian National Research, Development and Innovation Office (NKFIH) grant K-125015, a a PRODEX Experiment Agreement No. 4000137122, the Lendület LP2018-7/2021 grant of the Hungarian Academy of Science and the support of the city of Szombathely. V.V.G. is an F.R.S-FNRS Research Associate. NAW acknowledges UKSA grant ST/R004838/1. Funding text 2: Acknowledgements. CHEOPS is an ESA mission in partnership with Switzerland with important contributions to the payload and the ground segment from Austria, Belgium, France, Germany, Hungary, Italy, Portugal, Spain, Sweden, and the United Kingdom. The CHEOPS Consortium would like to gratefully acknowledge the support received by all the agencies, offices, universities, and industries involved. Their flexibility and willingness to explore new approaches were essential to the success of this mission. We thank the anonymous referee, whose valuable comments have improved the quality of the manuscript. DG gratefully acknowledges financial support from the CRT foundation under Grant No. 2018.2323 "Gaseousor rocky? Unveiling the nature of small worlds". JAEg and YAl acknowledge the support of the Swiss National Fund under grant 200020_172746. ML acknowledges support of the Swiss National Science Foundation under grant number PCEFP2_194576. SS have received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No 833925, project STAREX). S.G.S. acknowledges support from FCT through FCT contract nr. CEECIND/00826/2018 and POPH/FSE (EC). TWi and ACCa acknowledge support from STFC consolidated grant numbers ST/R000824/1 and ST/V000861/1, and UKSA grant number ST/R003203/1. The Belgian participation to CHEOPS has been supported by the Belgian Federal Science Policy Office (BELSPO) in the framework of the PRODEX Program, and by the University of Liège through an ARC grant for Concerted Research Actions financed by the Wallonia-Brussels Federation. L.D. is an F.R.S.-FNRS Postdoctoral Researcher. This work has been carried out within the framework of the NCCR PlanetS supported by the Swiss National Science Foundation under grants 51NF40_182901 and 51NF40_205606. LMS gratefully acknowledges financial support from the CRT foundation under Grant No. 2018.2323 'Gaseous or rocky? Unveiling the nature of small worlds'. We acknowledge support from the Spanish Ministry of Science and Innovation and the European Regional Development Fund through grants ESP2016-80435-C2-1-R, ESP2016-80435-C2-2-R, PGC2018-098153-B-C33, PGC2018-098153-B-C31, ESP2017-87676-C5-1-R, MDM-2017-0737 Unidad de Excelencia Maria de Maeztu-Centro de Astrobiología (INTA-CSIC), as well as the support of the Generalitat de Catalunya/CERCA programme. The MOC activities have been supported by the ESA contract No. 4000124370. S.C.C.B. acknowledges support from FCT through FCT contracts nr. IF/01312/2014/CP1215/CT0004. XB, SC, DG, MF and JL acknowledge their role as ESA-appointed CHEOPS science team members. LBo, VNa, IPa, GPi, RRa, and GSc acknowledge support from CHEOPS ASI-INAF agreement n. 2019-29-HH.0. ABr was supported by the SNSA. This project was supported by the CNES. This work was supported by FCT - Fundação para a Ciência e a Tecnologia through national funds and by FEDER through COMPETE2020 - Programa Operacional Competitividade e Internacionalizacão by these grants: UID/FIS/04434/2019, UIDB/04434/2020, UIDP/04434/2020, PTDC/FIS-AST/32113/2017 & POCI-01-0145-FEDER- 032113, PTDC/FIS-AST/28953/2017 & POCI-01-0145-FEDER-028953, PTDC/FIS-AST/28987/2017 & POCI-01-0145-FEDER-028987, O.D.S.D. is supported in the form of work contract (DL 57/2016/CP1364/CT0004) funded by national funds through FCT. B.-O. D. acknowledges support from the Swiss State Secretariat for Education, Research and Innovation (SERI) under contract number MB22.00046. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (project Four Aces. grant agreement No 724427). It has also been carried out in the frame of the National Centre for Competence in Research PlanetS supported by the Swiss National Science Foundation (SNSF). DE acknowledges financial support from the Swiss National Science Foundation for project 200021_200726. MF and CMP gratefully acknowledge the support of the Swedish National Space Agency (DNR 65/19, 174/18). M.G. is an F.R.S.-FNRS Senior Research Associate. SH gratefully acknowledges CNES funding through the grant 837319. KGI is the ESA CHEOPS Project Scientist and is responsible for the ESA CHEOPS Guest Observers Programme. She does not participate in, or contribute to, the definition of the Guaranteed Time Programme of the CHEOPS mission through which observations described in this paper have been taken, nor to any aspect of target selection for the programme. This work was granted access to the HPC resources of MesoPSL financed by the Region Ile de France and the project Equip@Meso (reference ANR-10-EQPX-29-01) of the programme Investissements d'Avenir supervised by the Agence Nationale pour la Recherche. PM acknowledges support from STFC research grant number ST/M001040/1. This work was also partially supported by a grant from the Simons Foundation (PI Queloz, grant number 327127). IRI acknowledges support from the Spanish Ministry of Science and Innovation and the European Regional Development Fund through grant PGC2018-098153-B- C33, as well as the support of the Generalitat de Catalunya/CERCA programme. GyMSz acknowledges the support of the Hungarian National Research, Development and Innovation Office (NKFIH) grant K-125015, a a PRODEX Experiment Agreement No. 4000137122, the Lendület LP2018-7/2021 grant of the Hungarian Academy of Science and the support of the city of Szombathely. V.V.G. is an F.R.S-FNRS Research Associate. NAW acknowledges UKSA grant ST/R004838/1.

PY - 2023/3/8

Y1 - 2023/3/8

N2 - 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 M⊕ (∼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 R⊕ (∼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 M⊕ and a thickness of 1.05-0.29+0.30 R⊕. 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.

AB - 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 M⊕ (∼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 R⊕ (∼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 M⊕ and a thickness of 1.05-0.29+0.30 R⊕. 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.

KW - Planets and satellites: fundamental parameters

KW - Stars: fundamental parameters

KW - Techniques: photometric

KW - Techniques: radial velocities

U2 - 10.1051/0004-6361/202245607

DO - 10.1051/0004-6361/202245607

M3 - Letter

SN - 0004-6361

VL - 671

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

M1 - L8

ER -

TOI-1055 b: Neptunian planet characterised with HARPS, TESS, and CHEOPS

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Projects

AO2 - Professor Andrew Cameron: Project AO2 - Andrew Cameron

Astronomy at St Andrews 2018-2021: Astronomy at St Andrews 2018-2021

Support for the PLATO Development: Support for the PLATO Development Phase 2017-2022: Planet candidate ranking and validation

Datasets

TOI-1055 b A neptunian planet characterised with HARPS, TESS, and CHEOPS. (2023) (dataset)

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