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TOI-674b: An oasis in the desert of exo-Neptunes transiting a nearby M dwarf

Murgas, F. and Astudillo-Defru, N. and Bonfils, X. and Crossfield, I. and Almenara, J. M. and Livingston, J. and Stassun, K. G. and Korth, J. and Orell-Miquel, J. and Morello, G. and Eastman, J. D. and Lissauer, J. J. and Kane, S. R. and Morales, F. Y. and Werner, M. W. and Gorjian, V. and Benneke, B. and Dragomir, D. and Matthews, E. C. and Howell, S. B. and Ciardi, D. and Gonzales, E. and Matson, R. and Beichman, C. and Schlieder, J. and Collins, K. A. and Collins, K. I. and Jensen, E. L. N. and Evans, P. and Pozuelos, F. J. and Gillon, M. and Jehin, E. and Barkaoui, K. and Artigau, E. and Bouchy, F. and Charbonneau, D. and Delfosse, X. and Díaz, R. F. and Doyon, R. and Figueira, P. and Forveille, T. and Lovis, C. and Melo, C. and Gaisné, G. and Pepe, F. and Santos, N. C. and Ségransan, D. and Udry, S. and Goeke, R. F. and Levine, A. M. and Quintana, E. V. and Guerrero, N. M. and Mireles, I. and Caldwell, D. A. and Tenenbaum, P. and Brasseur, C. E. and Ricker, G. and Vanderspek, R. and Latham, D. W. and Seager, S. and Winn, J. and Jenkins, J. M. (2021) TOI-674b: An oasis in the desert of exo-Neptunes transiting a nearby M dwarf. Astronomy and Astrophysics, 653 . Art. No. A60. ISSN 0004-6361. doi:10.1051/0004-6361/202140718.

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Context. The NASA mission TESS is currently doing an all-sky survey from space to detect transiting planets around bright stars. As part of the validation process, the most promising planet candidates need to be confirmed and characterized using follow-up observations. Aims. In this article, our aim is to confirm the planetary nature of the transiting planet candidate TOI-674b using spectroscopic and photometric observations. Methods. We use TESS, Spitzer, ground-based light curves, and HARPS spectrograph radial velocity measurements to establish the physical properties of the transiting exoplanet candidate TOI-674b. We perform a joint fit of the light curves and radial velocity time series to measure the mass, radius, and orbital parameters of the candidate. Results. We confirm and characterize TOI-674b, a low-density super-Neptune transiting a nearby M dwarf. The host star (TIC 158588995, V = 14.2 mag, J = 10.3 mag) is characterized by its M2V spectral type with M⋆ = 0.420 ± 0.010 M_⊙, R⋆ = 0.420 ± 0.013 R_⊙, and T_(eff) = 3514 ± 57 K; it is located at a distance d = 46.16 ± 0.03 pc. Combining the available transit light curves plus radial velocity measurements and jointly fitting a circular orbit model, we find an orbital period of 1.977143 ± 3 × 10⁻⁶ days, a planetary radius of 5.25 ± 0.17 R_⊕, and a mass of 23.6 ± 3.3 M⊕ implying a mean density of ρ_p =0.91 ± 0.15 g cm⁻³. A non-circular orbit model fit delivers similar planetary mass and radius values within the uncertainties. Given the measured planetary radius and mass, TOI-674b is one of the largest and most massive super-Neptune class planets discovered around an M-type star to date. It is found in the Neptunian desert, and is a promising candidate for atmospheric characterization using the James Webb Space Telescope.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Murgas, F.0000-0001-9087-1245
Morales, F. Y.0000-0001-9414-3851
Gorjian, V.0000-0002-8990-2101
Ciardi, D.0000-0002-5741-3047
Beichman, C.0000-0002-5627-5471
Additional Information:© ESO 2021. Article published by EDP Sciences. Received 3 March 2021; Accepted 1 June 2021; Published online 07 September 2021. N.A.-D. acknowledges the support of FONDECYT 3180063. D.D. acknowledges support from the TESS Guest Investigator Program grant 80NSSC19K1727 and NASA Exoplanet Research Program grant 18-2XRP18_2-0136. X.D., T.F., and G.G. acknowledge funding in the framework of the Investissements d’Avenir program (ANR-15-IDEX-02), through the funding of the “Origin of Life” project of the Univ. Grenoble-Alpes. G.M. has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 895525. This paper includes data collected by 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. 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 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. The research leading to these results has received funding from the ARC grant for Concerted Research Actions, financed by the Wallonia-Brussels Federation. TRAPPIST is funded by the Belgian Fund for Scientific Research (Fond National de la Recherche Scientifique, FNRS) under the grant FRFC 2.5.594.09.F, with the participation of the Swiss National Science Foundation (SNF). MG and EJ are F.R.S.-FNRS Senior Research Associate. Some of the Observations in the paper made use of the High-Resolution Imaging instrument Zorro. Zorro was funded by the NASA Exoplanet Exploration Program and built at the NASA Ames Research Center by Steve B. Howell, Nic Scott, Elliott P. Horch, and Emmett Quigley. Zorro was mounted on the Gemini South telescope of the international Gemini Observatory, a program of NSF’s OIR Lab, which is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation, on behalf of the Gemini partnership: the National Science Foundation (United States), National Research Council (Canada), Agencia Nacional de Investigación y Desarrollo (Chile), Ministerio de Ciencia, Tecnología e Innovación (Argentina), Ministério da Ciência, Tecnologia, Inovaçõese Comunicações (Brazil), and Korea Astronomy and Space Science Institute (Republic of Korea). 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 Internacionalização by these grants: UID/FIS/04434/2019; UIDB/04434/2020; UIDP/04434/2020; PTDC/FIS-AST/32113/2017 and POCI-01-0145-FEDER-032113; PTDC/FISAST/28953/2017 and POCI-01-0145-FEDER-028953. This work made use of tpfplotter by J. Lillo-Box (publicly available in, which also made use of the python packages astropy, lightkurve, matplotlib and numpy. This work makes use of observations from the Las Cumbres Observatory Global Telescope Network. This work made use of by Daniel Foreman-Mackey (Foreman-Mackey 2016).
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)3180063
Agence Nationale pour la Recherche (ANR)ANR-15-IDEX-02
University of GrenobleUNSPECIFIED
Marie Curie Fellowship895525
Australian Research CouncilUNSPECIFIED
Wallonia-Brussels FederationUNSPECIFIED
Fonds de la Recherche Scientifique (FNRS)2.5.594.09.F
Swiss National Science Foundation (SNSF)UNSPECIFIED
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/FISAST/28953/2017
Fundação para a Ciência e a Tecnologia (FCT)POCI-01-0145-FEDER-028953
Subject Keywords:planets and satellites: general – planets and satellites: gaseous planets – stars: individual: TOI-674 – techniques: photometric – techniques: radial velocities
Record Number:CaltechAUTHORS:20211005-231052401
Persistent URL:
Official Citation:TOI-674b: An oasis in the desert of exo-Neptunes transiting a nearby M dwarf. F. Murgas, N. Astudillo-Defru, X. Bonfils, I. Crossfield, J. M. Almenara, J. Livingston, K. G. Stassun, J. Korth, J. Orell-Miquel, G. Morello, J. D. Eastman, J. J. Lissauer, S. R. Kane, F. Y. Morales, M. W. Werner, V. Gorjian, B. Benneke, D. Dragomir, E. C. Matthews, S. B. Howell, D. Ciardi, E. Gonzales, R. Matson, C. Beichman, J. Schlieder, K. A. Collins, K. I. Collins, E. L. N. Jensen, P. Evans, F. J. Pozuelos, M. Gillon, E. Jehin, K. Barkaoui, E. Artigau, F. Bouchy, D. Charbonneau, X. Delfosse, R. F. Díaz, R. Doyon, P. Figueira, T. Forveille, C. Lovis, C. Melo, G. Gaisné, F. Pepe, N. C. Santos, D. Ségransan, S. Udry, R. F. Goeke, A. M. Levine, E. V. Quintana, N. M. Guerrero, I. Mireles, D. A. Caldwell, P. Tenenbaum, C. E. Brasseur, G. Ricker, R. Vanderspek, D. W. Latham, S. Seager, J. Winn and J. M. Jenkins. A&A, 653 (2021) A60; DOI:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:111232
Deposited By: Tony Diaz
Deposited On:06 Oct 2021 14:14
Last Modified:06 Oct 2021 14:14

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