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Published December 2023 | Version Published
Journal Article Open

TOI-1801 b: A temperate mini-Neptune around a young M0.5 dwarf

Creators

  • 1. ROR icon Instituto de Astrofísica de Canarias
  • 2. ROR icon University of La Laguna
  • 3. ROR icon Thüringer Landessternwarte Tautenburg
  • 4. ROR icon University of Turin
  • 5. ROR icon University of California, Berkeley
  • 6. ROR icon Centro de Astrobiología
  • 7. ROR icon University of Göttingen
  • 8. ROR icon Heidelberg University
  • 9. ROR icon University of Chicago
  • 10. ROR icon Instituto de Astrofísica de Andalucía
  • 11. ROR icon Chalmers University of Technology
  • 12. ROR icon NASA Exoplanet Science Institute
  • 13. ROR icon Harvard-Smithsonian Center for Astrophysics
  • 14. ROR icon Institut d'Estudis Espacials de Catalunya
  • 15. Public observatory ASTROLAB IRIS, Provinciaal Domein "De Palingbeek", Verbrandemolenstraat 5, 8902, Zillebeke, Ieper, Belgium
  • 16. Vereniging Voor Sterrenkunde (VVS), Oostmeers 122 C, 8000, Brugge, Belgium
  • 17. ROR icon KU Leuven
  • 18. ROR icon George Mason University
  • 19. ROR icon University of Tokyo
  • 20. ROR icon Universität Hamburg
  • 21. ROR icon University of Arizona
  • 22. ROR icon Institute of Space Sciences
  • 23. ROR icon Complutense University of Madrid
  • 24. ROR icon Nicolaus Copernicus University
  • 25. ROR icon Max Planck Institute for Astronomy
  • 26. ROR icon University of California, Santa Cruz
  • 27. ROR icon California Institute of Technology
  • 28. ROR icon University of Hawaii at Manoa
  • 29. ROR icon University of California, Riverside
  • 30. ROR icon Princeton University
  • 31. ROR icon University of Kansas
  • 32. ROR icon Space Telescope Science Institute
  • 33. ROR icon Ames Research Center
  • 34. ROR icon Johns Hopkins University
  • 35. ROR icon University of Sydney
  • 36. ROR icon University of California, Los Angeles
  • 37. Villa '39 Observatory, Landers, CA, 92285, USA
  • 38. ROR icon University of Oklahoma
  • 39. Kotizarovci Observatory, Sarsoni 90, 51216, Viskovo, Croatia
  • 40. ROR icon Mississippi State University
  • 41. ROR icon University of Notre Dame

Abstract

We report the discovery, mass, and radius determination of TOI-1801 b, a temperate mini-Neptune around a young M dwarf. TOI-1801 b was observed in TESS sectors 22 and 49, and the alert that this was a TESS planet candidate with a period of 21.3 days went out in April 2020. However, ground-based follow-up observations, including seeing-limited photometry in and outside transit together with precise radial velocity (RV) measurements with CARMENES and HIRES revealed that the true period of the planet is 10.6 days. These observations also allowed us to retrieve a mass of 5.74 ± 1.46 M⊕, which together with a radius of 2.08 ± 0.12 R⊕, means that TOI-1801 b is most probably composed of water and rock, with an upper limit of 2% by mass of H2 in its atmosphere. The stellar rotation period of 16 days is readily detectable in our RV time series and in the ground-based photometry. We derived a likely age of 600–800 Myr for the parent star TOI-1801, which means that TOI-1801 b is the least massive young mini-Neptune with precise mass and radius determinations. Our results suggest that if TOI-1801 b had a larger atmosphere in the past, it must have been removed by some evolutionary mechanism on timescales shorter than 1 Gyr.

Copyright and License

© 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.

Acknowledgement

This paper includes data collected by the TESS mission. Funding for the TESS mission is provided by the NASA Explorer Program. We acknowledge the use of public TOI Release data from pipelines at the TESS Science Office and at the TESS Science Processing Operations Center. 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. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. CARMENES is an instrument at the Centro Astronomico Hispano en Andalucia (CAHA) at Calar Alto (Almeria, Spain), operated jointly by the Junta de Andaluc a and the Instituto de Astrof sica de Andaluc a (CSIC). CARMENES was funded by the Max-Planck-Gesellschaft (MPG), the Consejo Superior de Investigaciones Cientificas (CSIC), the Ministerio de Econom a y Competitividad (MINECO) and the European Regional Development Fund (ERDF) through projects FICTS-2011-02, ICTS-2017-07-CAHA-4, and CAHA16-CE-3978, and the members of the CARMENES Consortium (Max-Planck-Institut für Astronomie, Instituto de Astrofisica de Andalucia, Landessternwarte Königstuhl, Institut de Ciències de l’Espai, Institut für Astrophysik Göttingen, Universidad Complutense de Madrid, Thüringer Landessternwarte Tautenburg, Instituto de Astrof sica de Canarias, Hamburger Sternwarte, Centro de Astrobiologia and Centro Astronomico Hispano-Alemán), with additional contributions by the MINECO, the Deutsche Forschungsgemeinschaft through the Major Research Instrumentation Programme and Research Unit FOR2544 “Blue Planets around Red Stars”, the Klaus Tschira Stiftung, the states of Baden-Württemberg and Niedersachsen, and by the Junta de Andalucía. This article is partly based on observations made with the MuSCAT2 instrument, developed by ABC, at Telescopio Carlos Sánchez operated on the island of Tenerife by the IAC in the Spanish Observatorio del Teide. Some of the observations in this paper made use of the High-Resolution Imaging instrument ’Alopeke and were obtained under Gemini LLP Proposal Number: GN/S-2021A-LP-105. ’Alopeke 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. Alopeke was mounted on the Gemini North 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, Tecnologia e Innovación (Argentina), Ministério da Ciência, Tecnologia, Inovações e Comunicações (Brazil), and Korea Astronomy and Space Science Institute (Republic of Korea). P.P.P., B.C., D.V. and M.R.M. would like to acknowledge the following iSHELL observers: Claire Geneser, Ahmad Sohani, John Berberian, Patrick Nercessian, Jennah Fayaz, Kevin I Collins and Ian Helm. P.P.P. would like to acknowledge support from NASA (Exoplanet Research Program Award #80NSSC20K0251, TESS Cycle 3 Guest Investigator Program Award #80NSSC21K0349, JPL Research and Technology Development, and Keck Observatory Data Analysis) and the NSF (Astronomy and Astrophysics Grants #1716202 and 2006517), and the Mt Cuba Astronomical Foundation. This work makes use of observations from the Las Cumbres Observatory global telescope network. Part of the LCOGT telescope time was granted by NOIRLab through the Mid-Scale Innovations Program (MSIP). MSIP is funded by NSF. The Joan Oró Telescope (TJO) of the Montsec Observatory (OdM) is owned by the Catalan Government and operated by the Institute for Space Studies of Catalonia (IEEC). Ariel Postdoctoral Fellowship program of the Swedish National Space Agency (SNSA). The results reported herein benefitted from collaborations and/or information exchange within NASA’s Nexus for Exoplanet System Science (NExSS) research coordination network sponsored by NASA’s Science Mission Directorate under Agreement No. 80NSSC21K0593 for the program “Alien Earths”. G.N. thanks for the research funding from the Ministry of Education and Science programme the “Excellence Initiative - Research University” conducted at the Centre of Excellence in Astrophysics and Astrochemistry of the Nicolaus Copernicus University in Toruń, Poland. This work is partly financed by the Spanish Ministry of Economics and Competitiveness through projects PGC2018-098153-B-C31, PID2019-109522GB-C5[1:4]. E. G. acknowledges the generous support from the Deutsche Forschungsgemeinschaft (DFG) of the grant HA3279/14-1. P.D. acknowledges support from a 51 Pegasi b Postdoctoral Fellowship from the Heising-Simons Foundation. D.H. acknowledges support from the Alfred P. Sloan Foundation, the National Aeronautics and Space Administration (80NSSC21K0652) and the Australian Research Council (FT200100871). This work is partly supported by JSPS KAKENHI Grant Numbers JP18H05439 and JST CREST Grant Number JPMJCR176.

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Additional details

Related works

Is new version of
Discussion Paper: arXiv:2310.10244 (arXiv)

Funding

National Aeronautics and Space Administration
80NSSC20K0251
National Aeronautics and Space Administration
80NSSC21K0349
Jet Propulsion Laboratory
JPL Research and Technology Development -
National Science Foundation
1716202
National Science Foundation
2006517
Mt. Cuba Astronomical Foundation
Nicolaus Copernicus University
Ministerio de Ciencia, Innovación y Universidades
PGC2018-098153-B-C31
Ministerio de Ciencia, Innovación y Universidades
PID2019-109522GB-C5
Deutsche Forschungsgemeinschaft
HA3279/14-1
Heising-Simons Foundation
51 Pegasi b Postdoctoral Fellowship -
Alfred P. Sloan Foundation
National Aeronautics and Space Administration
80NSSC21K0652
Australian Research Council
FT200100871
Japan Society for the Promotion of Science
JP18H05439
Japan Science and Technology Agency
JPMJCR176

Dates

Accepted
2023-10-04
Available
2023-12-13
Published online

Caltech Custom Metadata

Caltech groups
Infrared Processing and Analysis Center (IPAC), Division of Geological and Planetary Sciences (GPS), Division of Physics, Mathematics and Astronomy (PMA)
Publication Status
Published