학술논문
TOI-4860 b, a short-period giant planet transiting an M3.5 dwarf
Document Type
Working Paper
Author
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.; Nascimento, J. Dias do; 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.
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Subject
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Abstract
We report the discovery and characterisation of a giant transiting planet orbiting a nearby M3.5V dwarf (d = 80.4 pc, $G$ = 15.1 mag, $K$=11.2 mag, R$_\star$ = 0.358 $\pm$ 0.015 R$_\odot$, M$_\star$ = 0.340 $\pm$ 0.009 M$_\odot$). 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 $\pm$ 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 $\pm$ 0.12) and measured the mass of the planet (0.273 $\pm$ 0.006 M$_J$). Based on these measurements, TOI-4860 b joins the small set of massive planets ($>$80 M$_E$) found around mid to late M dwarfs ($<$0.4 R$_\odot$), providing both an interesting challenge to planet formation theory and a favourable target for further atmospheric studies with transmission spectroscopy. We identified an additional signal in the radial velocity data that we attribute to an eccentric planet candidate ($e=0.66\pm0.09$) with an orbital period of $427\pm7$~days and a minimum mass of $1.66\pm 0.26$ M$_J$, but additional data would be needed to confirm this.
Comment: 16 pages, 14 figures, accepted for publication in A&A
Comment: 16 pages, 14 figures, accepted for publication in A&A