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

November 2023 • 2023A&A...679A..70H

Authors • Hagelberg, J. • Nielsen, L. D. • Attia, M. • 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 M_J. 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. ★Tables A.1─A.3 are available at the CDS via anonymous ftp to cdsarc.cds.unistra.fr (130.79.128.5) or via https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/679/A70

Links

• PREPRINT http://arxiv.org/abs/2309.11390
• POSTSCRIPT https://www.aanda.org/10.1051/0004-6361/202244940/postscript
• ELECTR https://doi.org/10.1051%2F0004-6361%2F202244940
• SIMBAD https://simbad.u-strasbg.fr/simbad/sim-ref?querymethod=bib&simbo=on&submit=submit+bibcode&bibcode=2023A%26A...679A..70H
• PDF https://www.aanda.org/10.1051/0004-6361/202244940/pdf
• DATA http://archive.eso.org/bin/ads2eso?2023A%26A...679A..70H
• DATA https://irsa.ipac.caltech.edu/bibdata/2023/H/2023A&A...679A..70H.html