Issue |
A&A
Volume 696, April 2025
|
|
---|---|---|
Article Number | A233 | |
Number of page(s) | 21 | |
Section | Planets, planetary systems, and small bodies | |
DOI | https://doi.org/10.1051/0004-6361/202453026 | |
Published online | 29 April 2025 |
In-depth characterization of the Kepler-10 three-planet system with HARPS-N radial velocities and Kepler transit timing variations
1
INAF – Osservatorio Astrofisico di Torino,
via Osservatorio 20,
10025
Pino Torinese,
Italy
2
INAF – Osservatorio Astronomico di Padova,
Vicolo dell’Osservatorio 5,
35122
Padova,
Italy
3
Academy for the Mathematical Sciences, c/o Isaac Newton Institute for Mathematical Sciences,
20 Clarkson Road,
Cambridge
CB3 0EH,
UK
4
Astrophysics Group, Cavendish Laboratory, University of Cambridge,
JJ Thomson Avenue,
Cambridge
CB3 0HE,
UK
5
Department of Earth and Planetary Sciences, Harvard University,
20 Oxford Street,
Cambridge,
MA
02138,
USA
6
Département d’astronomie de l’Université de Genève,
Chemin Pegasi 51,
1290
Versoix,
Switzerland
7
Université Aix Marseille, CNRS, CNES, LAM,
Marseille,
France
8
Department of Physics, University of Oxford,
Oxford
OX1 3RH,
UK
9
Department of Physics, ETH Zurich,
Wolfgang-Pauli-Strasse 2,
8093
Zurich,
Switzerland
10
School of Physics & Astronomy, University of Birmingham, Edgbaston,
Birmingham
B15 2TT,
UK
11
Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università degli Studi di Padova,
Vicolo dell’Osservatorio 3,
35122
Padova,
Italy
12
Center for Astrophysics | Harvard & Smithsonian,
60 Garden Street,
Cambridge,
MA
02138,
USA
13
SUPA, Institute for Astronomy, University of Edinburgh,
Blackford Hill,
Edinburgh
EH9 3HJ,
UK
14
Centre for Exoplanet Science, University of Edinburgh,
Edinburgh
EH9 3FD,
UK
15
Dipartimento di Fisica, Università degli Studi di Milano,
Via Celoria 16,
20133
Milano,
Italy
16
DTU Space, Technical University of Denmark,
Elektrovej 328,
2800
Kgs. Lyngby,
Denmark
17
Centre for Exoplanet Science, SUPA School of Physics and Astronomy, University of St Andrews,
St Andrews,
Fife
KY16 9SS,
UK
18
Fundación Galileo Galilei – INAF,
Rambla José Ana Fernandez Pérez 7,
38712
Breña Baja, Tenerife,
Spain
19
Department of Astrophysics, University of Exeter,
Stocker Rd,
Exeter
EX4 4QL,
UK
20
Instituto de Astrofísica de Canarias (IAC),
38205
La Laguna, Tenerife,
Spain
21
Dipartimento di Fisica, Università degli Studi di Torino,
via Pietro Giuria 1,
10125
Torino,
Italy
22
INAF – Osservatorio Astronomico di Brera,
Via E. Bianchi 46,
23807
Merate,
Italy
★ Corresponding author; aldo.bonomo@inaf.it
Received:
15
November
2024
Accepted:
10
February
2025
The old G3V star Kepler-10 is known to host two transiting planets, the ultra-short-period super-Earth Kepler-10 b (Pb = 0.837 d; Rb = 1.47 R⊕) and the long-period sub-Neptune Kepler-10 c (Pc = 45.294 d; Rc = 2.35 R⊕), and a non-transiting planet that causes variations in the Kepler-10 c transit times. Measurements of the mass of Kepler-10 c in the literature have shown disagreement, depending on the radial-velocity dataset and/or the modeling technique used. Here we report on the analysis of almost 300 high-precision radial velocities gathered with the HARPS-N spectrograph at the Telescopio Nazionale Galileo over ∼11 years, and extracted with the YARARA-v2 tool, which corrects for possible systematics and/or low-level activity variations at the spectrum level. To model these radial velocities, we used three different noise models and various numerical techniques, which all converged to the solution: Mb = 3.24 ± 0.32 M⊕ (10σ) and ρb = 5.54 ± 0.64 g cm−3 for planet b; Mc = 11.29 ± 1.24 M⊕ (9σ) and ρc = 4.75 ± 0.53 g cm−3 for planet c; and Md sin i = 12.00 ± 2.15 M⊕ (6 σ) and Pd = 151.06 ± 0.48 d for the non-transiting planet Kepler-10 d. This solution is further supported by the analysis of the Kepler-10 c transit timing variations and their simultaneous modeling with the HARPS-N radial velocities. While Kepler-10 b is consistent with a rocky composition and a small or no iron core, Kepler-10 c may be a water world that formed beyond the water snowline and subsequently migrated inward.
Key words: techniques: photometric / techniques: radial velocities / planets and satellites: composition / planets and satellites: detection / planets and satellites: fundamental parameters
© The Authors 2025
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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