In-depth characterization of the Kepler-10 three-planet system with HARPS-N radial velocities and Kepler transit timing variations
Year: 2025
Type: article
Abstract: The old G3V star Kepler-10 is known to host two transiting planets, the ultra-short-period super-Earth Kepler-10 b (P$_b$ = 0.837 d; R$_b$ = 1.47 R$_{\bigoplus}$) and the long-period sub-Neptune Kepler-10 c (P$_c$ = 45.294 d; R$_c$ = 2.35 R$_{\bigoplus}$), 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: M$_b$ = 3.24 $\pm$ 0.32 M$_{\bigoplus}$ (10σ) and ρ$_b$ = 5.54 $\pm$ 0.64 g cm$^{-3}$ for planet b; M$_c$ = 11.29 $\pm$ 1.24 M$_{\bigoplus}$ (9σ) and ρ$_c$ = 4.75 $\pm$ 0.53 g cm$^{-3}$ for planet c; and M$_d$ sin i = 12.00 $\pm$ 2.15 M$_{\bigoplus}$ (6σ) and P$_d$ = 151.06 $\pm$ 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.
Authors: Bonomo, Aldo Stefano, Borsato, Luca, Rajpaul, Vinesh Maguire, Zeng, Li, Damasso, Mario, Hara, Nathan C., Cretignier, Michael, Leleu, Adrien, Unger, Nicolas, Dumusque, Xavier, Lienhard, Florian, Mortier, Annelies, Naponiello, Luca, Malavolta, Luca, Sozzetti, Alessandro, Latham, David W., Rice, Ken, Bongiolatti, Rachele, Buchhave, Lars A., Cameron, Andrew C., et al.
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W6929048447
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