학술논문
An M dwarf accompanied by a close-in giant orbiter with SPECULOOS
Document Type
Working Paper
Author
Triaud, Amaury H. M. J.; Dransfield, Georgina; Kagetani, Taiki; Timmermans, Mathilde; Narita, Norio; Barkaoui, Khalid; Hirano, Teruyuki; Rackham, Benjamin V.; Mori, Mayuko; Baycroft, Thomas; Benkhaldoun, Zouhair; Burgasser, Adam J.; Caldwell, Douglas A.; Collins, Karen A.; Davis, Yasmin T.; Delrez, Laetitia; Demory, Brice-Oliver; Ducrot, Elsa; Fukui, Akihiko; Muñoz, Clàudia Jano; Jehin, Emmanuël; García, Lionel J.; Ghachoui, Mourad; Gillon, Michaël; Chew, Yilen Gómez Maqueo; Hooton, Matthew J.; Ikoma, Masahiro; Kawauchi, Kiyoe; Kotani, Takayuki; Levine, Alan M.; Pallé, Enric; Pedersen, Peter P.; Pozuelos, Francisco J.; Queloz, Didier; Scutt, Owen J.; Seager, Sara; Sebastian, Daniel; Tamura, Motohide; Thompson, Samantha; Watanabe, Noriharu; de Wit, Julien; Winn, Joshua N.; Zúñiga-Fernández, Sebastián
Source
Subject
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Abstract
In the last decade, a dozen close-in giant planets have been discovered orbiting stars with spectral types ranging from M0 to M4, a mystery since known formation pathways do not predict the existence of such systems. Here, we confirm TOI-4860 b, a Jupiter-sized planet orbiting an M4.5 host, a star at the transition between fully and partially convective interiors. First identified with TESS data, we validate the transiting companion's planetary nature through multicolour photometry from the TRAPPIST-South/North, SPECULOOS, and MuSCAT3 facilities. Our analysis yields a radius of $0.76 \pm 0.02~ \rm R_{Jup}$ for the planet, a mass of $0.34~\rm M_\odot$ for the star, and an orbital period of 1.52 d. Using the newly commissioned SPIRIT InGaAs camera at the SPECULOOS-South Observatory, we collect infrared photometry in zYJ that spans the time of secondary eclipse. These observations do not detect a secondary eclipse, placing an upper limit on the brightness of the companion. The planetary nature of the companion is further confirmed through high-resolution spectroscopy obtained with the IRD spectrograph at Subaru Telescope, from which we measure a mass of $0.67 \pm 0.14~\rm M_{Jup}$ . Based on its overall density, TOI-4860 b appears to be rich in heavy elements, like its host star.
Comment: Accepted for publication in MNRAS Letters
Comment: Accepted for publication in MNRAS Letters