A super-Earth and a sub-Neptune orbiting the bright, quiet M3 dwarf TOI-1266

Demory, B.-O.; Pozuelos, F. J.; Gómez Maqueo Chew, Y.; Sabin, L.; Petrucci, R.; Schroffenegger, U.; Grimm, S. L.; Sestovic, M.; Gillon, M.; McCormac, J.; Barkaoui, K.; Benz, W.; Bieryla, A.; Bouchy, F.; Burdanov, A.; Collins, K. A.; de Wit, J.; Dressing, C. D.; Garcia, L. J.; Giacalone, S.; ... (2020). A super-Earth and a sub-Neptune orbiting the bright, quiet M3 dwarf TOI-1266. Astronomy and astrophysics, 642, A49. EDP Sciences 10.1051/0004-6361/202038616

[img] Text
aa38616-20.pdf - Published Version
Restricted to registered users only
Available under License Publisher holds Copyright.

Download (11MB) | Request a copy

We report the discovery and characterisation of a super-Earth and a sub-Neptune transiting the bright (K = 8.8), quiet, and nearby (37 pc) M3V dwarf TOI-1266. We validate the planetary nature of TOI-1266 b and c using four sectors of TESS photometry and data from the newly-commissioned 1-m SAINT-EX telescope located in San Pedro Mártir (México). We also include additional ground-based follow-up photometry as well as high-resolution spectroscopy and high-angular imaging observations. The inner, larger planet has a radius of R = 2.37−0.12+0.16 R⊕ and an orbital period of 10.9 days. The outer, smaller planet has a radius of R = 1.56−0.13+0.15 R⊕ on an 18.8-day orbit. The data are found to be consistent with circular, co-planar and stable orbits that are weakly influenced by the 2:1 mean motion resonance. Our TTV analysis of the combined dataset enables model-independent constraints on the masses and eccentricities of the planets. We find planetary masses of Mp = 13.5−9.0+11.0 M⊕ (<36.8 M⊕ at 2-σ) for TOI-1266 b and 2.2−1.5+2.0 M⊕ (<5.7 M⊕ at 2-σ) for TOI-1266 c. We find small but non-zero orbital eccentricities of 0.09−0.05+0.06 (<0.21 at 2-σ) for TOI-1266 b and 0.04 ± 0.03 (< 0.10 at 2-σ) for TOI-1266 c. The equilibrium temperatures of both planets are of 413 ± 20 and 344 ± 16 K, respectively, assuming a null Bond albedo and uniform heat redistribution from the day-side to the night-side hemisphere. The host brightness and negligible activity combined with the planetary system architecture and favourable planet-to-star radii ratios makes TOI-1266 an exquisite system for a detailed characterisation.

Item Type:

Journal Article (Original Article)


08 Faculty of Science > Physics Institute > Space Research and Planetary Sciences
10 Strategic Research Centers > Center for Space and Habitability (CSH)

UniBE Contributor:

Demory, Brice-Olivier Denys, Grimm, Simon Lukas, Sestovic, Marko, Benz, Willy, Heng, Kevin, Mordasini, Christoph


500 Science > 520 Astronomy
600 Technology > 620 Engineering




EDP Sciences




Brice-Olivier Denys Demory

Date Deposited:

04 Apr 2022 11:06

Last Modified:

02 Mar 2023 23:34

Publisher DOI:






Actions (login required)

Edit item Edit item
Provide Feedback