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.; GUERRA, P.; HALDEMANN, J.; HENG, K.; JEHIN, E.; JOFRÉ, E.; KANE, S. R.; LILLO-BOX, J.; MAIGNÉ, V.; MORDASINI, C.; MORRIS, B. M.; NIRAULA, P.; QUELOZ, D.; RACKHAM, B. V.; SAVEL, A. B.

ASTRONOMY AND ASTROPHYSICS

EDP SCIENCES S A

Lugar: Paris; Año: 2020 vol. 642

0004-6361

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⊕ (