A hot sub-Neptune in the desert and a temperate super-Earth around faint M dwarfs. Color validation of TOI-4479b and TOI-2081b

Esparza-Borges, E.; Parviainen, H.; Murgas, F.; Pallé, E.; Maas, A.; Morello, G.; Zapatero-Osorio, M. R.; Barkaoui, K.; Narita, N.; Fukui, A.; Casasayas-Barris, N.; Oshagh, M.; Crouzet, N.; Galán, D.; Fernández, G. E.; Kagetani, T.; Kawauchi, K.; Kodama, T.; Korth, J.; Kusakabe, N.; Laza-Ramos, A.; Luque, R.; Livingston, J.; Madrigal-Aguado, A.; Mori, M.; Orell-Miquel, J.; Puig-Subirà, M.; Stangret, M.; Terada, Y.; Watanabe, N.; Zou, Y.; Baliga Savel, A.; Belinski, A. A.; Collins, K.; Dressing, C. D.; Giacalone, S.; Gill, H.; Goliguzova, M. V.; Ikoma, M.; Jenkins, J. M.; Tamura, M.; Twicken, J. D.; Ricker, G. R.; Schwarz, R. P.; Seager, S.; Shporer, A.; Vanderspek, R.; Winn, J.
Bibliographical reference

Astronomy and Astrophysics

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Aims: We report the discovery and validation of two TESS exoplanets orbiting faint M dwarfs: TOI-4479b and TOI-2081b.
Methods: We jointly analyzed space (TESS mission) and ground-based (MuSCAT2, MuSCAT3 and SINISTRO instruments) light curves using our multicolor photometry transit analysis pipeline. This allowed us to compute contamination limits for both candidates and validate them as planet-sized companions.
Results: We found TOI-4479b to be a sub-Neptune-sized planet (Rp = 2.82−0.63+0.65 R⊕) and TOI-2081b to be a super-Earth-sized planet (Rp = 2.04−0.54+0.50 R⊕). Furthermore, we obtained that TOI-4479b, with a short orbital period of 1.15890−0.00001+0.00002 days, lies within the Neptune desert and is in fact the largest nearly ultra-short period planet around an M dwarf known to date.
Conclusions: These results make TOI-4479b rare among the currently known exoplanet population of M dwarf stars and an especially interesting target for spectroscopic follow-up and future studies of planet formation and evolution.