Characterising planetary systems with SPIRou: Temperate sub-Neptune exoplanet orbiting the nearby fully convective star GJ 1289 and a candidate around GJ 3378

被引：0

作者：

Moutou, C. ^{[1
]}

Ould-Elhkim, M. ^{[1
]}

Donati, J. -F ^{[1
]}

Charpentier, P. ^{[1
]}

Cadieux, C. ^{[3
]}

Delfosse, X. ^{[2
]}

Artigau, E. ^{[3
]}

Arnold, L. ^{[4
]}

Baruteau, C. ^{[1
]}

Carmona, A. ^{[2
]}

Cook, N. J. ^{[3
]}

Zuleta, P. Cortes ^{[5
]}

Doyon, R. ^{[3
]}

Hebrard, G. ^{[6
]}

机构：

[1] Univ Toulouse, CNRS, IRAP, 14 Ave Belin, F-31400 Toulouse, France

[2] Univ Montreal, Inst Trottier Rech Exoplanetes, 1375 Ave Therese Lavoie Roux, Montreal, PQ H2V 0B3, Canada

[3] Univ Grenoble Alpes, CNRS, IPAG, F-38000 Grenoble, France

[4] Canada France Hawaii Telescope, CNRS, Kamuela, HI 96743 USA

[5] Aix Marseille Univ, CNRS, CNES, LAM, Marseille, France

[6] Univ Paris 06, Inst Astrophys Paris, UMR7095 CNRS, 98 Bis Blvd Arago, F-75014 Paris, France

来源：

ASTRONOMY & ASTROPHYSICS | 2024年 / 688卷

基金：

欧洲研究理事会;

关键词：

instrumentation: spectrographs; techniques: radial velocities; stars: magnetic field; planetary systems; stars: individual: GJ 1289; stars: individual: GJ 3378; MAIN-SEQUENCE STARS; M DWARFS; STELLAR ACTIVITY; RADIAL-VELOCITY; SUPER-EARTH; HABITABLE ZONES; MAGNETIC-FIELDS; NO EVIDENCE; B SPIROU; MASS;

D O I：

10.1051/0004-6361/202450466

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We report the discovery of two new exoplanet systems around fully convective stars, found from the radial-velocity (RV) variations of their host stars measured with the nIR spectropolarimeter CFHT/SPIRou over multiple years. GJ 3378 b is a planet with minimum mass of 5.26(-0.97)(+0.94)M(circle plus) on an eccentric 24.73-day orbit around an M4V star of 0.26 M-circle dot. GJ 1289 b has a minimum mass of 6.27 +/- 1.25 M-circle dot in a 111.74-day orbit, on a circular orbit around an M4.5V star of mass 0.21 M-circle dot. Both stars are in the solar neighbourhood, at 7.73 and 8.86 pc, respectively. The low-amplitude RV signals are detected after line-by-line post-processing treatment. These potential sub-Neptune class planets around cool stars may have temperate atmospheres and be interesting nearby systems for further studies. We also recovered the large-scale magnetic field of both stars, found to be mostly axisymmetric and dipolar, with polar strengths of 20-30 G and 200-240 G for GJ 3378 (in 2019-2021) and GJ 1289 (in 2022-2023), respectively. The rotation periods measured with the magnetic field differ from the orbital periods and, in general, stellar activity is not seen in the studied nIR RV time series of both stars. GJ 3378 b detections have not been confirmed by optical RVs and, therefore, they are solely considered a candidate for the present purposes.

引用

页数：16