CaltechAUTHORS
Published December 3, 2021 | Version Supplemental Material
Journal Article Open

GJ 367b: A dense, ultrashort-period sub-Earth planet transiting a nearby red dwarf star

Creators

  • 1. ROR icon Technical University of Berlin
  • 2. ROR icon German Aerospace Center
  • 3. ROR icon Catholic University of the Most Holy Conception
  • 4. ROR icon Institut de Planétologie et d'Astrophysique de Grenoble
  • 5. ROR icon University of Turin
  • 6. ROR icon European Organisation for the Exploitation of Meteorological Satellites
  • 7. ROR icon Thüringer Landessternwarte Tautenburg
  • 8. ROR icon Keele University
  • 9. ROR icon University of Tokyo
  • 10. ROR icon Instituto de Astrofísica de Canarias
  • 11. ROR icon University of La Laguna
  • 12. ROR icon Harvard-Smithsonian Center for Astrophysics
  • 13. ROR icon Institut de Recherche sur les Lois Fondamentales de l'Univers
  • 14. ROR icon University of Paris-Saclay
  • 15. ROR icon Ames Research Center
  • 16. ROR icon University of Porto
  • 17. ROR icon California Institute of Technology
  • 18. ROR icon Massachusetts Institute of Technology
  • 19. ROR icon Princeton University
  • 20. ROR icon Aarhus University
  • 21. ROR icon University of Oxford
  • 22. ROR icon University of Geneva
  • 23. ROR icon Infrared Processing and Analysis Center
  • 24. ROR icon The University of Texas at Austin
  • 25. ROR icon Federal University of Rio Grande do Norte
  • 26. ROR icon National University of General San Martín
  • 27. ROR icon European Southern Observatory
  • 28. ROR icon Chalmers University of Technology
  • 29. ROR icon Leiden University
  • 30. ROR icon Rhenish Institute for Environmental Research
  • 31. ROR icon Las Cumbres Observatory Global Telescope Network
  • 32. ROR icon Astronomical Institute
  • 33. ROR icon Stanford University
  • 34. ROR icon Search for Extraterrestrial Intelligence
  • 35. ROR icon Japan Science and Technology Agency
  • 36. ROR icon Astrobiology Center
  • 37. ROR icon University College London
  • 38. ROR icon Freie Universität Berlin
  • 39. ROR icon Wesleyan University
  • 40. ROR icon Goddard Space Flight Center

Abstract

Ultrashort-period (USP) exoplanets have orbital periods shorter than 1 day. Precise masses and radii of USP exoplanets could provide constraints on their unknown formation and evolution processes. We report the detection and characterization of the USP planet GJ 367b using high-precision photometry and radial velocity observations. GJ 367b orbits a bright (V-band magnitude of 10.2), nearby, and red (M-type) dwarf star every 7.7 hours. GJ 367b has a radius of 0.718 ± 0.054 Earth-radii and a mass of 0.546 ± 0.078 Earth-masses, making it a sub-Earth planet. The corresponding bulk density is 8.106 ± 2.165 grams per cubic centimeter—close to that of iron. An interior structure model predicts that the planet has an iron core radius fraction of 86 ± 5%, similar to that of Mercury's interior.

Additional Information

© 2021 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. https://www.sciencemag.org/about/science-licenses-journal-article-reuse This is an article distributed under the terms of the Science Journals Default License. Received: 31 December 2020. Accepted: 12 October 2021. Published in print: 2 December 2021. We acknowledge use of observations from the LCOGT network. We made use of data from the European Space Agency (ESA) mission Gaia (www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC) (www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. 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 work was supported by the KESPRINT collaboration, an international consortium devoted to the characterization and research of exoplanets discovered with space-based missions. Some of the observations were made at Gemini South using the high-resolution imaging instrument Zorro, funded by the NASA Exoplanet Exploration Program and built at the NASA Ames Research Center by S. B. Howell, N. Scott, E. P. Horch, and E. 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); the National Research Council (Canada); Agencia Nacional de Investigacin y Desarrollo (Chile); Ministerio de Ciencia, Tecnologa e Innovacin (Argentina); Ministrio da Ciłncia, Tecnologia, Inovaes e Comunicaes (Brazil); and the Korea Astronomy and Space Science Institute (Republic of Korea). This is University of Texas Center for Planetary Systems Habitability Contribution no. 0041. K.W.F.L., Sz.Cs., M.E., S.G., A.P.H., and H.R. were supported by Deutsche Forschungsgemeinschaft grants PA525/18-1, PA525/19-1, PA525/20-1, HA3279/12-1, and RA714/14-1 within the DFG Schwerpunkt SPP 1992, Exploring the Diversity of Extrasolar Planets. Sz.Cs. is supported by Deutsche Forschungsgemeinschaft Research Unit 2440, Matter Under Planetary Interior Conditions: High Pressure Planetary and Plasma Physics. T.H. was supported by JSPS KAKENHI grant no. JP19K14783, and N.N. was supported by JSPS KAKENHI grant nos. JP18H01265 and JP18H05439 and JST PRESTO grant no. JPMJPR1775. J.L. is supported by JSPS KAKENHI grant no. JP20K14518. R.A.G. acknowledges support from PLATO and GOLF CNES grants. P.K. acknowledges support from the MSMT grant LTT20015. S.M. acknowledges support by the Spanish Ministry of Science and Innovation with the Ramon y Cajal fellowship no. RYC-2015-17697 and grant no. PID2019-107187GB-I00. N.C.S. was supported by Fundaçao para a Ciência e a Tecnologia through national funds and by FEDER through COMPETE2020 - Programa Operacional Competitividade e Internacionalização grants UID/FIS/04434/2019, UIDB/04434/2020, UIDP/04434/2020, PTDC/FIS-AST/32113/2017 and POCI-01-0145-FEDER-032113, and PTDC/FIS-AST/28953/2017 and POCI-01-0145-FEDER-028953. X.D. and G.G. acknowledge funding in the framework of the Investissements d'Avenir program (ANR-15-IDEX-02), Origin of Life project of the Université Grenoble-Alpes. J.R.D.M. acknowledges grants from CNPq, CAPES, and FAPERN Brazilian agencies. N.A.-D. acknowledges support from FONDECYT project 3180063. Resources for the production of the SPOC data products were provided by the NASA High-End Computing (HEC) program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center. S.A. is supported by the Danish National Research Foundation (grant agreement no. DNRF106). D.G. and L.M.S. acknowledge financial support from the Cassa di Risparmio di Torino foundation under grant no. 2018.2323, "Gaseous or rocky? Unveiling the nature of small worlds." Author contributions: K.W.F.L. contributed to the planet detection, transit light curve analysis, gyrochronology age estimate, and tidal evolution calculations and led the writing of the paper. Sz.Cs. performed the joint light curve and RV analysis using the Transit and Light Curve Modeller (TLCM). N.A.-D. and X.B. led the HARPS RV follow-up program and reduced and analyzed the RV data. D.G. performed the frequency analysis of the RV and activity indicators. F.D., O.B., A.P.H., and R.L. analyzed the RV data. S.P. determined the interior composition of the planet and modeled the precursor gaseous planet. M.E. performed the Rapid Eye Mount (REM) robotic telescope observations and analysis. M.E. and A.M.S.S. derived the light curve dilution factor. C.H., K.W.F.L., S.M., and R.A.G. determined the stellar rotation period using WASP data. S.B.H. analyzed the speckle imaging data. T.H. and M.F. performed the spectral analysis using SpecMatch-Emp, and T.H. derived the stellar parameters using an MCMC simulation. J.L. performed stellar characterization using isochrone fitting. F.M. performed the LCOGT and HARPS observations. K.A.C. coordinated the TESS SG1 working group. K.A.C. and P.L. analyzed the ground-based photometric observations. N.C.S. performed spectral characterization using ODUSSEAS. M.C.J. determined the Galactic space velocities of the star. K.W.F.L. and S.R. calculated the emission spectroscopy metric. J.K. performed transit-timing variation (TTV) analysis. J.C., P.E., and S.G. analyzed the light curve for planet detection. E.Gu. analyzed the activity indicators. G.R.R., R.V., D.W.L., S.S., J.N.W., and J.M.J. led and organized the TESS mission, including the observations, processing of the data, working groups coordination, target selection, and dissemination of the data products. E.H.M., M.V., and J.E.S. are members of the TESS POC who coordinated and scheduled the TESS science observations and conducted instrument planning. R.M., J.C.S., and J.D.T. are members of the SPOC who performed data calibration, light curve production, and transit planet detection. D.C., J.C., and S.N.Q. are members of the TSO who reviewed the data and performed planet candidate vetting. J.M.A., E.A., F.B., D.C., J.R.D.M., X.D., R.F.D., R.D., P.F., T.F., G.G., C.L., C.M., F.P., D.S., and S.U. are coinvestigators of the proposal, which provided the HARPS observations of the target and supported the interpretation of results. S.A., P.C., A.C., W.D.C., E.Go., I.G., P.K., E.K., J.J.L., N.N., H.L.M.O., E.P., C.M.P., H.R., L.M.S., J.Š., and V.V.E. are part of the KESPRINT consortium and contributed to the interpretation of the results. All authors contributed to the preparation of the paper. Data and materials availability: The TESS photometric observations are available at the Mikulski Archive for Space Telescopes (MAST) at https://exo.mast.stsci.edu under target name TOI 731.01. The raw HARPS spectroscopic data are available on the ESO Science Archive Facility http://archive.eso.org/cms.html under ESO program IDs 072.C-0488, 082.C-0718, 183.C-0437 (primary investigators: M. Mayor and X. Bonfils), and 1102.C-0339 (primary investigator: X. Bonfils). The ground-based photometry obtained by the LCO telescope and REM as well as the Gemini imaging data are available on the Exoplanet Follow-up Observing Program (ExoFOP) website https://exofop.ipac.caltech.edu/tess/ under target name TOI 731.01. The raw Gemini data are available at https://archive.gemini.edu/searchform under program ID GS-2021A-LP-105. The archival WASP data are available on the NASA Exoplanet Archive https://exoplanetarchive.ipac.caltech.edu/docs/SuperWASPMission.html under object name GJ 367. Our reduced RVs and activity indices are listed in tables S1 and S2 and in machine-readable form in data S1 and S2. The TLCM is available at www.transits.hu/. The authors declare no competing interests.

Attached Files

Supplemental Material - science.aay3253_data_s1_and_s2.zip

Supplemental Material - science.aay3253_sm.pdf

Files

science.aay3253_data_s1_and_s2.zip

Files (3.2 MB)

Name Size
md5:84b4fa45e8e9ed385d0cc3ca614068e3
10.8 kB Preview Download
md5:3d8182528e0ec6379efd1af1cfe3047c
3.1 MB Preview Download

Additional details

Identifiers

Eprint ID
112189
DOI
10.1126/science.aay3253
Resolver ID
CaltechAUTHORS:20211203-174947953

Related works

Describes
10.1126/science.aay3253 (DOI)

Funding

Deutsche Forschungsgemeinschaft (DFG)
PA525/18-1
Deutsche Forschungsgemeinschaft (DFG)
PA525/19-1
Deutsche Forschungsgemeinschaft (DFG)
PA525/20-1
Deutsche Forschungsgemeinschaft (DFG)
HA3279/12-1
Deutsche Forschungsgemeinschaft (DFG)
RA714/14-1
Deutsche Forschungsgemeinschaft (DFG)
SPP 1992
Deutsche Forschungsgemeinschaft (DFG)
2440
Japan Society for the Promotion of Science (JSPS)
JP19K14783
Japan Society for the Promotion of Science (JSPS)
JP18H01265
Japan Society for the Promotion of Science (JSPS)
JP18H05439
Japan Science and Technology Agency
JPMJPR1775
Japan Society for the Promotion of Science (JSPS)
JP20K14518
Centre National d'Études Spatiales (CNES)
Ministry of Education, Youth and Sports (Czech Republic)
LTT20015
Ramón y Cajal Programme
RYC-2015-17697
Ministerio de Ciencia e Innovación (MCINN)
PID2019-107187GB-I00
Fundaçao para a Ciência e a Tecnologia (FCT)
Fundo Europeu de Desenvolvimento Regional (FEDER)
UID/FIS/04434/2019
Fundo Europeu de Desenvolvimento Regional (FEDER)
UIDB/04434/2020
Fundo Europeu de Desenvolvimento Regional (FEDER)
UIDP/04434/2020
Fundo Europeu de Desenvolvimento Regional (FEDER)
PTDC/FIS-AST/32113/2017
Fundo Europeu de Desenvolvimento Regional (FEDER)
POCI-01-0145-FEDER-032113
Fundo Europeu de Desenvolvimento Regional (FEDER)
PTDC/FIS-AST/28953/2017
Fundo Europeu de Desenvolvimento Regional (FEDER)
POCI-01-0145-FEDER-028953
Agence Nationale pour la Recherche (ANR)
ANR-15-IDEX-02
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Fundação de Apoio à Pesquisa do RN (FAPERN)
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)
3180063
Danish National Research Foundation
DNRF106
Cassa di Risparmio di Torino Foundation
2018.2323

Dates

Created
2021-12-03
Created from EPrint's datestamp field
Updated
2021-12-03
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Infrared Processing and Analysis Center (IPAC)