TOI-4860 b, a short-period giant planet transiting an M3.5 dwarf

• Published in: Astronomy and astrophysics (Berlin) 2024-03, Vol.683, p.A166
• Main Authors: Almenara, J. M., Bonfils, X., Bryant, E. M., Jordán, A., Hébrard, G., Martioli, E., Correia, A. C. M., Astudillo-Defru, N., Cadieux, C., Arnold, L., Artigau, É., Bakos, G. Á., Barros, S.C.C., Bayliss, D., Bouchy, F., Boué, G., Brahm, R., Carmona, A., Charbonneau, D., Ciardi, D. R., Cloutier, R., Cointepas, M., Cook, N. J., Cowan, N. B., Delfosse, X., Dias do Nascimento, J., Donati, J.-F., Doyon, R., Forveille, T., Fouqué, P., Gaidos, E., Gilbert, E. A., da Silva, J. Gomes, Hartman, J. D., Hesse, K., Hobson, M. J., Jenkins, J. M., Kiefer, F., Kostov, V. B., Laskar, J., Lendl, M., L’Heureux, A., Martins, J. H. C., Menou, K., Moutou, C., Murgas, F., Polanski, A. S., Rapetti, D., Sedaghati, E., Shang, H.
• Format: Article
• Language: English
• Subjects: Sciences of the Universe
• ISSN: 0004-6361; 1432-0746; 1432-0756
• DOI: 10.1051/0004-6361/202346999

We report the discovery and characterisation of a giant transiting planet orbiting a nearby M3.5V dwarf ( d = 80.4pc, G = 15.1 mag, K =11.2mag, R * = 0.358 ± 0.015 R ⊙ , M * = 0.340 ± 0.009 M ⊙ ). Using the photometric time series from TESS sectors 10, 36, 46, and 63 and near-infrared spectrophotometry from ExTrA, we measured a planetary radius of 0.77 ± 0.03 R J and an orbital period of 1.52 days. With high-resolution spectroscopy taken by the CFHT/SPIRou and ESO/ESPRESSO spectrographs, we refined the host star parameters ([Fe/H] = 0.27 ± 0.12) and measured the mass of the planet (0.273 ± 0.006 M J ). Based on these measurements, TOI-4860 b joins the small set of massive planets (>80 M E ) found around mid to late M dwarfs (