TOI-858 B b: A hot Jupiter on a polar orbit in a loose binary

Hagelberg, J.; Nielsen, L. D.; Attia, O.; Bourrier, V.; Pearce, L.; Venturini, J.; Winn, J. N.; Bouchy, F.; Bouma, L. G.; Briceño, C.; Collins, K. A.; Davis, A. B.; Eastman, J. D.; Evans, P.; Falk, B.; Grieves, N.; Guerrero, N. M.; Hellier, C.; Jones, M. I.; Latham, D. W.; Law, N.; Mann, A. W.; Marmier, M.; Ottoni, G.; Radford, D. J.; Restori, N.; Rudat, A.; Dos Santos, L.; Seager, S.; Stassun, K.; Stockdale, C.; Udry, S.; Wang, S.; Ziegler, C.

Abstract

We report the discovery of a hot Jupiter on a 3.28-day orbit around a 1.08 M⊙ G0 star that is the secondary component in a loose binary system. Based on follow-up radial velocity observations of TOI-858 B with CORALIE on the Swiss 1.2 m telescope and CHIRON on the 1.5 m telescope at the Cerro Tololo Inter-American Observatory (CTIO), we measured the planet mass to be 1.10−0.07+0.08 MJ. Two transits were further observed with CORALIE to determine the alignment of TOI-858 B b with respect to its host star. Analysis of the Rossiter-McLaughlin signal from the planet shows that the sky-projected obliquity is λ = 99.3−3.7+3.8°. Numerical simulations show that the neighbour star TOI-858 A is too distant to have trapped the planet in a Kozai–Lidov resonance, suggesting a different dynamical evolution or a primordial origin to explain this misalignment. The 1.15 M⊙ primary F9 star of the system (TYC 8501-01597-1, at ρ ~11″) was also observed with CORALIE in order to provide upper limits for the presence of aplanetary companion orbiting that star.

Citation

Hagelberg, J., Nielsen, L. D., Attia, O., Bourrier, V., Pearce, L., Venturini, J., …Ziegler, C. (2023). TOI-858 B b: A hot Jupiter on a polar orbit in a loose binary. Astronomy & Astrophysics, 679, Article A70. https://doi.org/10.1051/0004-6361/202244940

• Journal Article Type: Article
• Acceptance Date: Aug 17, 2023
• Online Publication Date: Nov 8, 2023
• Publication Date: 2023-11
• Deposit Date: Mar 12, 2024
• Journal: Astronomy & Astrophysics
• Print ISSN: 0004-6361
• Electronic ISSN: 1432-0746
• Publisher: EDP Sciences
• Peer Reviewed: Peer Reviewed
• Volume: 679
• Article Number: A70
• DOI: https://doi.org/10.1051/0004-6361/202244940
• Keywords: Space and Planetary Science; Astronomy and Astrophysics