Hidden Gems in TESS: sherlock finds two new rocky planets around nearby M dwarfs
astro-ph.EP
/ Authors
M. Timmermans, M. Dévora-Pajares, F. J. Pozuelos, K. Barkaoui, B. Rojas-Ayala, J. M. Almenara, S. B. Howell, A. H. M. J. Triaud, M. Gillon, M. G. Scott
and 18 more authors
Y. T. Davis, B. V. Rackham, A. J. Burgasser, X. Bonfils, K. A. Collins, B. -O. Demory, G. Dransfield, E. Ducrot, A. Fukui, M. Ghachoui, Y. Gómez Maqueo Chew, E. Jehin, N. Narita, P. P. Pedersen, R. P. Schwarz, G. Srdoc, S. Yalcinkaya, Z. Way
/ Abstract
The Hidden Gems project searches the TESS data for additional planets transiting low-mass stars in confirmed systems. Our goal is to identify planet candidates that are below the detection threshold set by the SPOC and QLP pipelines using sherlock, a specialized pipeline for robust detection and vetting of transit signals in TESS data. We present the discovery of two inner rocky planets in the TOI-237 and TOI-4336 A systems, confirmed with ground-based photometry from the TRAPPIST, SPECULOOS, ExTrA, and LCO facilities. TOI-237 c has a radius of 1.21 +/- 0.04Re, orbits its mid-M host star every 1.74 days, and is close to a 3:1 mean-motion resonance with TOI-237 b. TOI-4336 A c has a radius of 1.17 +/- 0.06Re, and orbits with a period of 7.58 days an M3.5 host star which is part of a hierarchical triple system. We performed model comparison to search for non-zero eccentricities, and found that the circular transit models are statistically favored. Dynamical simulations show that both systems are in stable configurations, and the TTVs expected for the TOI-237 system are of the order of seconds. TOI-237 c and TOI-4336 A c join the high-interest population of warm likely super-Earths below the so-called "radius valley". In particular, TOI-237 c is a good candidate for phase curve observations with JWST/MIRI thanks to the small radius of the host star and its short period.