✨ 3 Earth-sized planets discovered around twin stars

The exploration of binary star systems reveals surprises that challenge our conceptions of planetary formation. Thanks to NASA's TESS satellite, specialized in hunting exoplanets, an international team has identified three terrestrial-sized worlds orbiting twin stars in the TOI-2267 system, located approximately 190 light-years from our planet.

The discovery of these planets in a compact binary system is particularly significant because theoretical models predicted that intense gravitational forces between two close stars should prevent the formation and stability of elaborate planetary systems. Yet, analysis of TESS data combined with observations from the SPECULOOS and TRAPPIST telescope networks confirmed the presence of three rocky celestial bodies, with two transiting in front of one star and the third in front of its stellar companion.


The unique characteristics of TOI-2267 make it an exceptional case in the exoplanet catalog. Francisco J. Pozuelos, co-director of the study, emphasizes that this is the most compact and coldest binary system ever observed hosting planets, thus setting several records. The proximity of the two stars, which orbit each other creating an extremely dynamic environment, challenges the predictions of current planetary formation models.

The detection methods employed by researchers played a decisive role in this breakthrough. The SHERLOCK software enabled the identification of initial signals in TESS data, while the SPECULOOS observatories, optimized for studying small exoplanets around faint stars, provided the complementary observations necessary for precise characterization of the system. This multi-instrument approach revealed the unexpected planetary architecture of TOI-2267.

The implications of this discovery extend far beyond the system itself. Sebastián Zúñiga-Fernández, a member of the research team, explains that TOI-2267 constitutes an ideal natural laboratory for studying how rocky planets can form and persist in hostile dynamic conditions. The James Webb Space Telescope and future ground-based observatories will be able to analyze the atmospheric composition and physical properties of these worlds.


This breakthrough opens new perspectives for understanding the diversity of planetary architectures in our galaxy. The presence of Earth-sized planets in an environment as turbulent as that of a compact binary system suggests that planetary formation processes might be more resilient than previously thought, thereby expanding the field of possibilities in the search for habitable worlds elsewhere in the Universe.

Binary star systems and their influence on planetary formation

Binary star systems consist of two stars orbiting each other under the effect of their mutual attraction. This stellar configuration represents approximately half of the stellar systems in our galaxy, making it a common environment for planetary formation.

The gravitational interaction between the two stars creates forces that can disrupt protoplanetary disks, those rings of gas and dust where planets form. In compact binary systems where stars are particularly close, these forces can prevent the aggregation of matter into planetary bodies or eject nascent planets from the system.

The discovery of TOI-2267 demonstrates that planetary formation can nevertheless occur in these turbulent environments. Planets that manage to form there must develop stable orbits despite constant gravitational perturbations, which implies potentially different formation mechanisms from those observed around single stars.

The study of these systems allows astronomers to test the limits of planetary formation models and better understand how planets can emerge in various astrophysical conditions, including the most extreme ones.