Issue |
A&A
Volume 668, December 2022
|
|
---|---|---|
Article Number | A158 | |
Number of page(s) | 20 | |
Section | Planets and planetary systems | |
DOI | https://doi.org/10.1051/0004-6361/202244459 | |
Published online | 19 December 2022 |
HD 20329b: An ultra-short-period planet around a solar-type star found by TESS★
1
Instituto de Astrofísica de Canarias (IAC),
38205
La Laguna, Tenerife, Spain
e-mail: fmurgas@iac.es
2
Departamento de Astrofísica, Universidad de La Laguna (ULL),
38206
La Laguna, Tenerife, Spain
3
Instituto de Astrofísica de Andalucía (IAA-CSIC),
Glorieta de la Astronomía s/n,
18008
Granada, Spain
4
NASA Exoplanet Science Institute-Caltech/IPAC,
1200 E. California Blvd.
Pasadena, CA
91125, USA
5
Department of Physics, Engineering and Astronomy, Stephen F. Austin State University,
1936 North St,
Nacogdoches, TX
75962, USA
6
Cerro Tololo Inter-American Observatory,
Casilla 603,
La Serena, Chile
7
Department of Physics and Astronomy, The University of North Carolina at Chapel Hill,
Chapel Hill, NC
27599-3255, USA
8
Komaba Institute for Science, The University of Tokyo,
3-8-1 Komaba, Meguro,
Tokyo
153-8902, Japan
9
Department of Multi-Disciplinary Sciences, Graduate School of Arts and Sciences, The University of Tokyo,
3-8-1 Komaba, Meguro,
Tokyo
153-8902, Japan
10
Southwest Research Institute,
6220 Culebra Rd,
San Antonio, TX
78238, USA
11
Division of Geological and Planetary Sciences,
1200 E California Blvd,
Pasadena, CA
91125, USA
12
Department of Space, Earth and Environment, Astronomy and Plasma Physics, Chalmers University of Technology,
412 96
Gothenburg, Sweden
13
Department of Space, Earth and Environment, Chalmers University of Technology, Onsala Space Observatory,
439 92
Onsala, Sweden
14
Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology,
Cambridge, MA
02139, USA
15
McDonald Observatory, The University of Texas at
Austin, TX
78712, USA
16
Center for Planetary Systems Habitability, The University of Texas at Austin,
Austin, TX
78712, USA
17
Mullard Space Science Laboratory, University College London,
Holmbury St Mary, Dorking,
Surrey
RH5 6NT, UK
18
Department of Astrophysical Sciences, Princeton University,
Princeton, NJ
08544, USA
19
Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology,
Cambridge, MA
02139, USA
20
Department of Aeronautics and Astronautics, Massachusetts Institute of Technology,
Cambridge, MA
02139, USA
21
NASA Ames Research Center,
Moffett Field, CA
94035, USA
22
Center for Astrophysics ∣ Harvard & Smithsonian,
60 Garden Street,
Cambridge, MA
02138, USA
23
Dipartimento di Fisica, Università di Torino,
via P. Giuria 1,
I-10125
Torino, Italy
24
Thüringer Landessternwarte Tautenburg,
Sternwarte 5,
07778
Tautenburg, Germany
25
Astrobiology Center,
2-21-1 Osawa, Mitaka,
Tokyo
181-8588, Japan
26
National Astronomical Observatory of Japan,
2-21-1 Osawa, Mitaka,
Tokyo
181-8588, Japan
27
Department of Astronomy, The Graduate University for Advanced Studies (SOKENDAI),
2-21-1 Osawa, Mitaka,
Tokyo, Japan
28
Department of Astronomy & Astrophysics, University of Chicago,
Chicago, IL
60637, USA
29
Institute of Planetary Research, German Aerospace Center (DLR),
Rutherfordstrasse 2,
12489
Berlin, Germany
30
Astronomical Institute of the Czech Academy of Sciences,
Fričova 298,
25165,
Ondřejov, Czech Republic
31
INAF – Osservatorio Astronomico di Padova,
Vicolo dell’Osservatorio 5,
35122
Padova, Italy
Received:
8
July
2022
Accepted:
2
November
2022
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 Teff = 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 ρp = 8.06 ± 1.53 g cm−3. HD 20329b joins the ~30 currently known USP planets with radius and Doppler mass measurements.
Key words: planets and satellites: detection / techniques: radial velocities / techniques: photometric
Tables A.1 and A.2 are only available at the CDS via anonymous ftp to cdsarc.cds.unistra.fr (130.79.128.5) or via https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/668/A158
© F. Murgas et al. 2022
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.
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