Published December 2022 | Version public
Journal Article

HD 20329b: An ultra-short-period planet around a solar-type star found by TESS

  • 1. ROR icon Instituto de Astrofísica de Canarias
  • 2. ROR icon University of La Laguna
  • 3. ROR icon Instituto de Astrofísica de Andalucía
  • 4. ROR icon University of Chicago
  • 5. ROR icon Chalmers University of Technology
  • 6. ROR icon German Aerospace Center
  • 7. ROR icon University College London
  • 8. ROR icon The University of Texas at Austin
  • 9. ROR icon University of Turin
  • 10. ROR icon Thüringer Landessternwarte Tautenburg
  • 11. ROR icon Astronomical Institute
  • 12. ROR icon Astrobiology Center
  • 13. ROR icon National Astronomical Observatory of Japan
  • 14. ROR icon The Graduate University for Advanced Studies, SOKENDAI
  • 15. ROR icon Southwest Research Institute
  • 16. ROR icon Osservatorio Astronomico di Padova
  • 17. ROR icon University of Tokyo
  • 18. ROR icon NASA Exoplanet Science Institute
  • 19. ROR icon Stephen F. Austin State University
  • 20. ROR icon Cerro Tololo Inter-American Observatory
  • 21. ROR icon University of North Carolina at Chapel Hill
  • 22. ROR icon Ames Research Center
  • 23. ROR icon Harvard-Smithsonian Center for Astrophysics
  • 24. ROR icon Massachusetts Institute of Technology
  • 25. ROR icon Princeton University

Abstract

Context. Ultra-short-period (USP) planets are defined as planets with orbital periods shorter than one day. This type of planets is rare, highly irradiated, and interesting because their formation history is unknown. Aims. We aim to obtain precise mass and radius measurements to confirm the planetary nature of a USP candidate found by the Transiting Exoplanet Survey Satellite (TESS). These parameters can provide insights into the bulk composition of the planet candidate and help to place constraints on its formation history. Methods. We used TESS light curves and HARPS-N spectrograph radial velocity measurements to establish the physical properties of the transiting exoplanet candidate found around the star HD 20329 (TOI-4524). We performed 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 HD 20329b, a USP planet transiting a solar-type star. The host star (HD 20329, V = 8.74 mag, J = 7.5 mag) is characterized by its G5 spectral type with M_* = 0.90 ± 0.05 M_⊙, R_* = 1.13 ± 0.02 R_⊙, and T_(eff) = 5596 ± 50 K; it is located at a distance d = 63.68 ± 0.29 pc. By jointly fitting the available TESS transit light curves and follow-up radial velocity measurements, we find an orbital period of 0.9261 ± (0.5 × 10⁻⁴) days, a planetary radius of 1.72 ± 0.07 R_⊗, and a mass of 7.42 ± 1.09 M_⊗, implying a mean density of ρ_p = 8.06 ± 1.53 g cm⁻³. HD 20329b joins the ~30 currently known USP planets with radius and Doppler mass measurements.

Additional Information

T.M. acknowledges financial support from the Spanish Ministry of Science and Innovation (MICINN) through the Spanish State Research Agency, under the Severo Ochoa Program 2020-2023 (CEX2019-000920-S) as well as support from the ACIISI, Consejería de Economía, Conocimiento y Empleo del Gobierno de Canarias and the European Regional Development Fund (ERDF) under grant with reference PROID2021010128. R.L. acknowledges funding from University of La Laguna through the Margarita Salas Fellowship from the Spanish Ministry of Universities ref. UNI/551/2021-May 26 under the EU Next Generation funds and financial support from the Spanish Ministerio de Ciencia e Innovación, through project PID2019-109522GB-C52, and the Centre of Excellence "Severo Ochoa" award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709). PK acknolwedges the support from grant LTT-20015. K.W.F.L. was supported by Deutsche Forschungsgemeinschaft grants RA714/14-1 within the DFG Schwerpunkt SPP 1992, Exploring the Diversity of Extrasolar Planets. HJD acknowledges support from the Spanish Research Agency of the Ministry of Science and Innovation (AEI-MICINN) under the grant PID2019-107061GB-C66, DOI: 10.13039/501100011033. C.M.P. and J.K. gratefully acknowledge the support of the Swedish National Space Agency (DNR 65/19 2020-00104). 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. We acknowledge the use of public TESS 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. This publication makes use of data products from the AAVSO Photometric All Sky Survey (APASS). Funded by the Robert Martin Ayers Sciences Fund and the National Science Foundation. 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. This work made use of tpfplotter by J. Lillo-Box (publicly available in www.github.com/jlillo/tpfplotter), which also made use of the python packages astropy, lightkurve, matplotlib and numpy. This work is partly supported by JSPS KAKENHI Grant Numbers JP17H04574, JP18H05442, JST CREST Grant Number JPMJCR1761, and the Astrobiology Center of National Institutes of Natural Sciences (NINS) (Grant Number AB031010). This paper is 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.

Additional details

Identifiers

Eprint ID
119043
Resolver ID
CaltechAUTHORS:20230203-893794600.51

Funding

Centro de Excelencia Severo Ochoa
CEX2019-000920-S
Agencia Canaria de Investigación, Innovación y Sociedad de la Información (ACIISI)
European Regional Development Fund
PROID2021010128
Ministerio de Universidades
UNI/551/2021-May 26
Ministerio de Ciencia e Innovación (MCINN)
PID2019-109522GB-C52
Severo Ochoa
SEV-2017-0709
Ministry of Education, Youth and Sports (Czech Republic)
LTT-20015
Deutsche Forschungsgemeinschaft (DFG)
RA714/14-1
Ministerio de Ciencia e Innovación (MCINN)
PID2019-107061GB-C66
Swedish National Space Agency
65/19 2020-00104
NASA/JPL/Caltech
Robert Martin Ayers Sciences Fund
NSF
Gaia Multilateral Agreement
Japan Society for the Promotion of Science (JSPS)
JP17H04574
Japan Society for the Promotion of Science (JSPS)
JP18H05442
Japan Science and Technology Agency
JPMJCR1761
National Institutes of Natural Sciences of Japan
AB031010

Dates

Created
2023-03-02
Created from EPrint's datestamp field
Updated
2023-03-02
Created from EPrint's last_modified field