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TOI-220 b: a warm sub-Neptune discovered by TESS

Hoyer, S. and Gandolfi, D. and Armstrong, D. J. and Deleuil, M. and Acuña, L. and de Medeiros, J. R. and Goffo, E. and Lillo-Box, J. and Delgado Mena, E. and Lopez, T. A. and Santerne, A. and Sousa, S. and Fridlund, M. and Adibekyan, V. and Collins, K. A. and Serrano, L. M. and Cortés-Zuleta, P. and Howell, S. B. and Deeg, H. and Aguichine, A. and Barragán, O. and Bryant, E. M. and Canto Martins, B. L. and Collins, K. I. and Cooke, B. F. and Díaz, R. F. and Esposito, M. and Furlan, E. and Hojjatpanah, S. and Jackman, J. and Jenkins, J. M. and Jensen, E. L. N. and Latham, D. W. and Leão, I. C. and Matson, R. A. and Nielsen, L. D. and Osborn, A. and Otegi, J. F. and Rodler, F. and Sabotta, S. and Scott, N. J. and Seager, S. and Stockdale, C. and Strøm, P. A. and Vanderspek, R. and Van Eylen, V. and Wheatley, P. J. and Winn, J. N. and Almenara, J. M. and Barrado, D. and Barros, S. C. C. and Bayliss, D. and Bouchy, F. and Boyd, P. T. and Cabrera, J. and Cochran, W. D. and Demangeon, O. and Doty, J. P. and Dumusque, X. and Figueira, P. and Fong, W. and Grziwa, S. and Hatzes, A. P. and Kabáth, P. and Knudstrup, E. and Korth, J. and Livingston, J. H. and Luque, R. and Mousis, O. and Mullally, S. E. and Osborn, H. P. and Pallé, E. and Persson, C. M. and Redfield, S. and Santos, N. C. and Smith, J. and Šubjak, J. and Twicken, J. D. and Udry, S. and Yahalomi, D. A. (2021) TOI-220 b: a warm sub-Neptune discovered by TESS. Monthly Notices of the Royal Astronomical Society, 505 (3). pp. 3361-3379. ISSN 0035-8711. doi:10.1093/mnras/stab1427.

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In this paper, we report the discovery of TOI-220 b, a new sub-Neptune detected by the Transiting Exoplanet Survey Satellite (TESS) and confirmed by radial velocity follow-up observations with the HARPS spectrograph. Based on the combined analysis of TESS transit photometry and high precision radial velocity measurements, we estimate a planetary mass of 13.8 ± 1.0 M⊕ and radius of 3.03 ± 0.15 R⊕, implying a bulk density of 2.73 ± 0.47 gcm⁻³⁠. TOI-220 b orbits a relative bright (V= 10.4) and old (10.1 ± 1.4 Gyr) K dwarf star with a period of ∼10.69 d. Thus, TOI-220 b is a new warm sub-Neptune with very precise mass and radius determinations. A Bayesian analysis of the TOI-220 b internal structure indicates that due to the strong irradiation it receives, the low density of this planet could be explained with a steam atmosphere in radiative–convective equilibrium and a supercritical water layer on top of a differentiated interior made of a silicate mantle and a small iron core.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Hoyer, S.0000-0003-3477-2466
Gandolfi, D.0000-0001-8627-9628
Armstrong, D. J.0000-0002-5080-4117
Lopez, T. A.0000-0001-6622-1250
Santerne, A.0000-0002-3586-1316
Sousa, S.0000-0001-9047-2965
Fridlund, M.0000-0002-0855-8426
Serrano, L. M.0000-0001-9211-3691
Howell, S. B.0000-0002-2532-2853
Deeg, H.0000-0003-0047-4241
Barragán, O.0000-0003-0563-0493
Collins, K. I.0000-0003-2781-3207
Cooke, B. F.0000-0002-8824-9956
Díaz, R. F.0000-0001-9289-5160
Furlan, E.0000-0001-9800-6248
Jackman, J.0000-0003-0711-7992
Jenkins, J. M.0000-0002-4715-9460
Jensen, E. L. N.0000-0002-4625-7333
Latham, D. W.0000-0001-9911-7388
Matson, R. A.0000-0001-7233-7508
Nielsen, L. D.0000-0002-5254-2499
Osborn, A.0000-0002-5899-7750
Sabotta, S.0000-0001-9078-5574
Scott, N. J.0000-0003-1038-9702
Seager, S.0000-0002-6892-6948
Strøm, P. A.0000-0002-7823-1090
Vanderspek, R.0000-0001-6763-6562
Van Eylen, V.0000-0001-5542-8870
Wheatley, P. J.0000-0003-1452-2240
Winn, J. N.0000-0002-4265-047X
Almenara, J. M.0000-0003-3208-9815
Barros, S. C. C.0000-0003-2434-3625
Bayliss, D.0000-0001-6023-1335
Boyd, P. T.0000-0003-0442-4284
Cochran, W. D.0000-0001-9662-3496
Demangeon, O.0000-0001-7918-0355
Knudstrup, E.0000-0001-7880-594X
Korth, J.0000-0002-0076-6239
Livingston, J. H.0000-0002-4881-3620
Luque, R.0000-0002-4671-2957
Osborn, H. P.0000-0002-4047-4724
Redfield, S.0000-0003-3786-3486
Twicken, J. D.0000-0002-6778-7552
Udry, S.0000-0001-7576-6236
Additional Information:© 2021 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model ( Accepted 2021 May 4. Received 2021 May 4; in original form 2020 October 20. Published: 22 May 2021. SH acknowledges the Centre National d’Etudes Spatiales (CNES) funding through the grant 837319. MD acknowledges the CNES support. VA, EDM, SGS, NCS, SCCB, and SHoj acknowledge support by FCT – Fundação para a Ciência e a Tecnologia (Portugal) through national funds and by FEDER through COMPETE2020 – Programa Operacional Competitividade e Internacionalização 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. VA, EDM, SCCB, SGS, and ODSD further acknowledge the support from FCT through Investigador FCT contracts IF/00650/2015/CP1273/CT0001, IF/00849/2015/CP1273/CT0003, IF/01312/2014/CP1215/CT0004,CEECIND/00826/2018–POPH/FSE(EC), and DL57/2016/CP1364/ CT0004, respectively. SHoj further acknowledges the support by FCT through the fellowship PD/BD/128119/2016. DJA acknowledges support from the STFC via an Ernest Rutherford Fellowship (ST/R00384X/1). LMS and DG gratefully acknowledge financial support from the CRT foundation under Grant No. 2018.2323 ‘Gaseous or rocky? Unveiling the nature of small worlds’. JRM, BLCM, and ICL acknowledge continuous grants from the brazilian funding agencies CNPq, CAPES, and FAPERN. This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brasil (CAPES)-Finance Code 001. PK and JS acknowledge the MSMT INTER-TRANSFER grant LTT20015. This paper includes data collected with the TESS mission, which are publicly available from the Mikulski Archive for Space Telescopes (MAST). Funding for the TESS mission is provided by NASA’s Science Mission directorate. We acknowledge the use of public TESS Alert data from pipelines at the TESS Science Office and at the TESS Science Processing Operations Center. This research has made use of the Exoplanet Follow-up Observation Program website, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center for the production of the SPOC data products. This research has made use of computing facilities operated by CeSAM data center at LAM, Marseille, France; and the Data & Analysis Center for Exoplanets (DACE), which is a facility based at the University of Geneva (CH) dedicated to extrasolar planets data visualization, exchange, and analysis. DACE is a platform of the Swiss National Centre of Competence in Research (NCCR) PlanetS, federating the Swiss expertise in Exoplanet research. This research has made use of data obtained from the portal of The Extrasolar Planets Encyclopaedia. This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. This work makes use of observations from the LCOGT network. DG warmly thanks Alessia Barbiero and Pietro Giordano for the inspiring conversations at the time the HARPS follow-up of TOI-220 was started in 2018 November. Software: We gratefully acknowledge the open source software which made this work possible: astropy (Astropy Collaboration 2013; Price-Whelan et al. 2018), ipython (Pérez & Granger 2007), numpy (Van Der Walt, Colbert & Varoquaux 2011), scipy (Jones et al. 2001), matplotlib (Hunter 2007), jupyter (Kluyver et al. 2016), pandas (McKinney 2010; Pandas development team. 2020). Facilities: TESS, ESO: 3.6 m (HARPS spectrograph), Gemini: South (Zorro), LCOGT, Exoplanet Archive This work is based on observations made with ESO Telescopes at the La Silla Observatory under programs ID 1102.C-0923, 1102.C-0249, 0102.C-0584, 60.A.9700, and 60.A-9709. Data Availability: The TESS photometric data used in this work is available via Mikulski Archive for Space Telescopes (MAST) archive and TFOP program. Radial velocity measurements and the derived stellar activity indicators are provided in Tables G1 and G2, respectively. These tables are also available in digital form in the online version of the manuscript.
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Centre National d'Études Spatiales (CNES)837319
Fondo Europeo de Desarrollo Regional (FEDER)COMPETE2020
Fundação para a Ciência e a Tecnologia (FCT)UID/FIS/04434/2019
Fundação para a Ciência e a Tecnologia (FCT)UIDB/04434/2020
Fundação para a Ciência e a Tecnologia (FCT)UIDP/04434/2020
Fundação para a Ciência e a Tecnologia (FCT)PTDC/FIS-AST/32113/2017
Fundação para a Ciência e a Tecnologia (FCT)POCI-01-0145-FEDER-032113
Fundação para a Ciência e a Tecnologia (FCT)PTDC/FIS-AST/28953/2017
Fundação para a Ciência e a Tecnologia (FCT)POCI-01-0145-FEDER-028953
Fundação para a Ciência e a Tecnologia (FCT)IF/00650/2015/CP1273/CT0001
Fundação para a Ciência e a Tecnologia (FCT)IF/00849/2015/CP1273/CT0003
Fundação para a Ciência e a Tecnologia (FCT)IF/01312/2014/CP1215/CT0004
Fundação para a Ciência e a Tecnologia (FCT)CEECIND/00826/2018-POPH/FSE
Fundação para a Ciência e a Tecnologia (FCT)DL57/2016/CP1364/CT0004
Fundação para a Ciência e a Tecnologia (FCT)PD/BD/128119/2016
Science and Technology Facilities Council (STFC)ST/R00384X/1
CRT Foundation2018.2323
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)UNSPECIFIED
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)UNSPECIFIED
Fundação de Apoio à Pesquisa do RN (FAPERN)UNSPECIFIED
Subject Keywords:techniques: photometric – techniques: radial velocities – planets and satellites: fundamental parameters – planets and satellites: individual: TYC 8897-01263-1 – stars: fundamental parameters
Issue or Number:3
Record Number:CaltechAUTHORS:20210916-173248237
Persistent URL:
Official Citation:S Hoyer, D Gandolfi, D J Armstrong, M Deleuil, L Acuña, J R de Medeiros, E Goffo, J Lillo-Box, E Delgado Mena, T A Lopez, A Santerne, S Sousa, M Fridlund, V Adibekyan, K A Collins, L M Serrano, P Cortés-Zuleta, S B Howell, H Deeg, A Aguichine, O Barragán, E M Bryant, B L Canto Martins, K I Collins, B F Cooke, R F Díaz, M Esposito, E Furlan, S Hojjatpanah, J Jackman, J M Jenkins, E L N Jensen, D W Latham, I C Leão, R A Matson, L D Nielsen, A Osborn, J F Otegi, F Rodler, S Sabotta, N J Scott, S Seager, C Stockdale, P A Strøm, R Vanderspek, V Van Eylen, P J Wheatley, J N Winn, J M Almenara, D Barrado, S C C Barros, D Bayliss, F Bouchy, P T Boyd, J Cabrera, W D Cochran, O Demangeon, J P Doty, X Dumusque, P Figueira, W Fong, S Grziwa, A P Hatzes, P Kabáth, E Knudstrup, J Korth, J H Livingston, R Luque, O Mousis, S E Mullally, H P Osborn, E Pallé, C M Persson, S Redfield, N C Santos, J Smith, J Šubjak, J D Twicken, S Udry, D A Yahalomi, TOI-220 b: a warm sub-Neptune discovered by TESS, Monthly Notices of the Royal Astronomical Society, Volume 505, Issue 3, August 2021, Pages 3361–3379,
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:110920
Deposited By: Tony Diaz
Deposited On:16 Sep 2021 18:13
Last Modified:16 Sep 2021 18:13

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