Published January 11, 2024
| Version v1
Journal article
The SOPHIE search for northern extrasolar planets
Creators
- Heidari, N.
- Boisse, I.
- Hara, N
- Wilson, T
- Kiefer, F.
- Hébrard, G.
- Philipot, F.
- Hoyer, S.
- Stassun, K
- Henry, G
- Santos, N
- Acuña, L.
- Almasian, D.
- Arnold, L.
- Astudillo-Defru, N.
- Attia, O.
- Bonfils, X.
- Bouchy, F.
- Bourrier, V.
- Collet, B.
- Cortés-Zuleta, P.
- Carmona, A.
- Delfosse, X.
- Dalal, S.
- Deleuil, M.
- Demangeon, O
- Díaz, R
- Dumusque, X.
- Ehrenreich, D.
- Forveille, T.
- Hobson, M
- Jenkins, J
- Jenkins, J
- Lagrange, A
- Latham, D
- Larue, P.
- Liu, J.
- Moutou, C.
- Mignon, L.
- Osborn, H
- Pepe, F.
- Rapetti, D.
- Rodrigues, J.
- Santerne, A.
- Segransan, D.
- Shporer, A.
- Sulis, S.
- Torres, G.
- Udry, S.
- Vakili, F.
- Vanderburg, A.
- Venot, O.
- Vivien, H
- Vines, J
Contributors
Others:
- Laboratoire d'Astrophysique de Marseille (LAM) ; Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)
- Institut d'Astrophysique de Paris (IAP) ; Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
- Joseph Louis LAGRANGE (LAGRANGE) ; Université Nice Sophia Antipolis (1965 - 2019) (UNS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur ; Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)
- Observatoire de la Côte d'Azur (OCA) ; Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
- Shahid Beheshti University
- Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA) ; Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris ; Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)
- Institut de Planétologie et d'Astrophysique de Grenoble (IPAG) ; Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ) ; Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France
- Institut de recherche en astrophysique et planétologie (IRAP) ; Université Toulouse III - Paul Sabatier (UT3) ; Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP) ; Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) ; Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS)
- Programme National de Planétologie (PNP) of CNRS (INSU)
Description
Transiting planets with orbital periods longer than 40 d are extremely rare among the 5000+ planets discovered so far. The lack of discoveries of this population poses a challenge to research into planetary demographics, formation, and evolution. Here, we present the detection and characterization of HD 88986 b, a potentially transiting sub-Neptune, possessing the longest orbital period among known transiting small planets (<4 R ⊕ ) with a precise mass measurement ( σ M /M > 25%). Additionally, we identified the presence of a massive companion in a wider orbit around HD 88986. To validate this discovery, we used a combination of more than 25 yr of extensive radial velocity (RV) measurements (441 SOPHIE data points, 31 ELODIE data points, and 34 HIRES data points), Gaia DR3 data, 21 yr of photometric observations with the automatic photoelectric telescope (APT), two sectors of TESS data, and a 7-day observation of CHEOPS. Our analysis reveals that HD 88986 b, based on two potential single transits on sector 21 and sector 48 which are both consistent with the predicted transit time from the RV model, is potentially transiting. The joint analysis of RV and photometric data show that HD 88986 b has a radius of 2.49 ± 0.18 R ⊕ , a mass of 17.2 −3.8 +4.0 M ⊕ , and it orbits every 146.05 −0.40 +0.43 d around a subgiant HD 88986 which is one of the closest and brightest exoplanet host stars (G2Vtype, R = 1.543 ± 0.065 R ⊙ , V = 6.47 ± 0.01 mag, distance = 33.37 ± 0.04 pc). The nature of the outer, massive companion is still to be confirmed; a joint analysis of RVs, H IPPARCOS , and Gaia astrometric data shows that with a 3 σ confidence interval, its semi-major axis is between 16.7 and 38.8 au and its mass is between 68 and 284 M Jup . HD 88986 b's wide orbit suggests the planet did not undergo significant mass loss due to extreme-ultraviolet radiation from its host star. Therefore, it probably maintained its primordial composition, allowing us to probe its formation scenario. Furthermore, the cold nature of HD 88986 b (460 ± 8 K), thanks to its long orbital period, will open up exciting opportunities for future studies of cold atmosphere composition characterization. Moreover, the existence of a massive companion alongside HD 88986 b makes this system an interesting case study for understanding planetary formation and evolution.
Abstract
International audienceAdditional details
Identifiers
- URL
- https://insu.hal.science/insu-04433639
- URN
- urn:oai:HAL:insu-04433639v1
Origin repository
- Origin repository
- UNICA