Authors

Nathan Hara, Observatoire Astronomique de l’Université de GenèveFollow
François Bouchy, Observatoire Astronomique de l’Université de GenèveFollow
Manu Stalport, Observatoire Astronomique de l’Université de GenèveFollow
Isabelle Boisse, Aix-Marseille UniversitéFollow
J. Rodrigues, Observatoire Astronomique de l’Université de Genéve
Jean-Baptiste Delisle, Observatoire Astronomique de l’Université de Genéve
Alexandre Santerne, Aix-Marseille UniversitéFollow
Gregory W. Henry, Tennessee State UniversityFollow
Luc Arnold, Observatoire de Haute-ProvenceFollow
Nicola Astudillo-Defru, Universidad Católica de la Santísima ConcepciónFollow
Simon Borgniet, Université Grenoble AlpesFollow
Xavier Bonfils, Université Grenoble AlpesFollow
Vincent Bourrier, Observatoire Astronomique de l’Université de GenèveFollow
Bastien Brugger, Aix-Marseille UniversitéFollow
B. Courcol, Aix-Marseille UniversitéFollow
Shweta Dalal, Institut d’Astrophysique de ParisFollow
Magali Deleuil, Aix-Marseille UniversitéFollow
Xavier Delfosse, Université Grenoble AlpesFollow
Olivier Demangeon, Universidade do PortoFollow
Rodrigo F. Díaz, Universidad de Buenos AiresFollow
Xavier Dumusque, Observatoire Astronomique de l’Université de GenèveFollow
Thierry Forveille, Université Grenoble AlpesFollow
Guillaume Hébrard, Institut d’Astrophysique de ParisFollow
Melissa J. Hobson, Pontificia Universidad Católica de ChileFollow
‪Flavien Kiefer, Institut d’Astrophysique de ParisFollow
Théodore Lopez, Aix-Marseille UniversitéFollow
‪Lucile Mignon, Université Grenoble AlpesFollow
Olivier Mousis, Aix-Marseille UniversitéFollow
Claire Moutou, Aix-Marseille UniversitéFollow
Francesco Pepe, Observatoire Astronomique de l’Université de GenèveFollow
Javiera Rey, Observatoire Astronomique de l’Université de GenéveFollow
Nuno C. Santos, Universidade do PortoFollow
Damien Ségransan, Observatoire Astronomique de l’Université de GenèveFollow
Stéphane Udry, Observatoire Astronomique de l’Université de GenèveFollow
Paul Anthony Wilson, Universidade do PortoFollow

Document Type

Article

Publication Date

4-16-2020

Abstract

Aims. Since 2011, the SOPHIE spectrograph has been used to search for Neptunes and super-Earths in the northern hemisphere. As part of this observational program, 290 radial velocity measurements of the 6.4 V magnitude star HD 158259 were obtained. Additionally, TESS photometric measurements of this target are available. We present an analysis of the SOPHIE data and compare our results with the output of the TESS pipeline.

Methods. The radial velocity data, ancillary spectroscopic indices, and ground-based photometric measurements were analyzed with classical and ℓ1 periodograms. The stellar activity was modeled as a correlated Gaussian noise and its impact on the planet detection was measured with a new technique.

Results. The SOPHIE data support the detection of five planets, each with m sin i ≈ 6 M⊕, orbiting HD 158259 in 3.4, 5.2, 7.9, 12, and 17.4 days. Though a planetary origin is strongly favored, the 17.4 d signal is classified as a planet candidate due to a slightly lower statistical significance and to its proximity to the expected stellar rotation period. The data also present low frequency variations, most likely originating from a magnetic cycle and instrument systematics. Furthermore, the TESS pipeline reports a significant signal at 2.17 days corresponding to a planet of radius ≈1.2 R⊕. A compatible signal is seen in the radial velocities, which confirms the detection of an additional planet and yields a ≈2 M⊕ mass estimate.

Conclusions. We find a system of five planets and a strong candidate near a 3:2 mean motion resonance chain orbiting HD 158259. The planets are found to be outside of the two and three body resonances.

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