Two Warm Earth-sized Exoplanets And An Earth-sized Candidate In The M5V-M6V Binary System TOI-2267

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.

S. Zúñiga-Fernández, F. J. Pozuelos, M. Dévora-Pajares, N. Cuello, M. Greklek-McKeon, K. G. Stassun, V. Van Grootel, B. Rojas-Ayala, J. Korth, M. N. Günther, A. J. Burgasser, C. Hsu, B. V. Rackham, K. Barkaoui, M. Timmermans, C. Cadieux, R. Alonso, I. A. Strakhov, S. B. Howell, C. Littlefield, E. Furlan, P. J. Amado, J. M. Jenkins, J. D. Twicken, M. Sucerquia, Y. T. Davis, N. Schanche, K. A. Collins, A. Burdanov, F. Davoudi, B.-O. Demory, L. Delrez, G. Dransfield, E. Ducrot, L. J. Garcia, M. Gillon, Y. Gómez Maqueo Chew, C. Janó Muñoz, E. Jehin, C. A. Murray, P. Niraula, P. P. Pedersen, D. Queloz, R. Rebolo-López, M. G. Scott, D. Sebastian, M. J. Hooton, S. J. Thompson, A. H. M. J. Triaud, J. de Wit, M. Ghachoui, Z. Benkhaldoun, R. Doyon, D. Lafrenière, V. Casanova, A. Sota, I. Plauchu-Frayn, A. Khandelwal, F. Zong Lang, U. Schroffenegger, S. Wampfler, M. Lendl, R. P. Schwarz, F. Murgas, E. Palle, H. Parviainen

Comments: 18 pages article, 12 pages Appendix. Accepted for publication in A&A. Corresponding authors: S. Zúñiga-Fernández and F. J. Pozuelos
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:2508.14176 [astro-ph.EP] (or arXiv:2508.14176v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2508.14176
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Submission history
From: Sebastián Zúñiga-Fernández
[v1] Tue, 19 Aug 2025 18:01:10 UTC (17,106 KB)
https://arxiv.org/abs/2508.14176

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