We report two warm Earth-sized exoplanets orbiting the close binary TOI-2267 (M5+M6, separation ~8 au). Data from TESS and ground-based facilities confirm the planets, but we cannot determine which star they orbit. The planets have radii of 1.00+/-0.11 R_Earth (TOI-2267 b, P=2.28 d) and 1.14+/-0.13 R_Earth (TOI-2267 c, P=3.49 d) if around TOI-2267A, or 1.22+/-0.29 R_Earth and 1.36+/-0.33 R_Earth if around TOI-2267B. TESS also shows a candidate signal (TOI-2267.02, P=2.03 d, 0.95+/-0.12 or 1.13+/-0.30 R_Earth). Dynamical analysis shows all three cannot orbit one star; the most stable configuration has planets b and c (near a 3:2 resonance) orbiting one star and the candidate the other. This scenario would make TOI-2267 the most compact binary system known to host planets, with both components harbouring transiting worlds, offering a unique benchmark for studying planet formation and evolution in compact binary.
@article{arxiv.2508.14176,
title = {Two warm Earth-sized exoplanets and an Earth-sized candidate in the M5V-M6V binary system TOI-2267},
author = {S. Zúñiga-Fernández and F. J. Pozuelos and M. Dévora-Pajares and N. Cuello and M. Greklek-McKeon and K. G. Stassun and V. Van Grootel and B. Rojas-Ayala and J. Korth and M. N. Günther and A. J. Burgasser and C. Hsu and B. V. Rackham and K. Barkaoui and M. Timmermans and C. Cadieux and R. Alonso and I. A. Strakhov and S. B. Howell and C. Littlefield and E. Furlan and P. J. Amado and J. M. Jenkins and J. D. Twicken and M. Sucerquia and Y. T. Davis and N. Schanche and K. A. Collins and A. Burdanov and F. Davoudi and B. -O. Demory and L. Delrez and G. Dransfield and E. Ducrot and L. J. Garcia and M. Gillon and Y. Gómez Maqueo Chew and C. Janó Muñoz and E. Jehin and C. A. Murray and P. Niraula and P. P. Pedersen and D. Queloz and R. Rebolo-López and M. G. Scott and D. Sebastian and M. J. Hooton and S. J. Thompson and A. H. M. J. Triaud and J. de Wit and M. Ghachoui and Z. Benkhaldoun and R. Doyon and D. Lafrenière and V. Casanova and A. Sota and I. Plauchu-Frayn and A. Khandelwal and F. Zong Lang and U. Schroffenegger and S. Wampfler and M. Lendl and R. P. Schwarz and F. Murgas and E. Palle and H. Parviainen},
journal= {arXiv preprint arXiv:2508.14176},
year = {2025}
}
Comments
18 pages article, 12 pages Appendix. Accepted for publication in A&A. Corresponding authors: S. Z\'u\~niga-Fern\'andez and F. J. Pozuelos