Pesquisadores of Universidade of Nova Gales of Sul identified 27 new circumbinary planet candidates by analyzing continuous data from NASA’s TESS satellite. The discovery, published in the journal Monthly Notices of the Royal Astronomical Society, used an innovative methodology based on the periapsis shift in eclipsing binary stars. The finding circumvents significant limitations of conventional detection techniques and expands understanding of the real population of worlds orbiting double star systems.
Candidate planets orbit systems where two suns gravitate around each other. The research led by Margo Thornton represents a crucial advance in detecting worlds whose orbital geometry would make them completely invisible to ground-based telescopes using traditional methods. Nenhuma definitive confirmation has been achieved to date, but additional observations with radial velocity techniques are ongoing.
Why the transit method fails in binary systems
The transit method, the dominant technique for discovering exoplanets, works by detecting the slight dimming that a planet causes as it passes in front of its host star. Accuracy depends on a rigorous geometric condition: the planet’s orbital plane must be aligned perpendicularly with the Earth’s perspective. Para circumbinary planets, this requirement becomes extremely restrictive.
If a planet’s orbital plane is tilted by just one degree relative to the plane of the binary orbit, transits do not occur at regular, detectable intervals. Toda a class of circumbinary planets — those with highly inclined orbits — remained invisible to observers. Thornton explains that previous observational data reflected an intrinsic bias: only planets with specific orientations were found, preventing full understanding of how worlds arise in binary systems.
Periapsis displacement as a revolutionary tool
The new method took advantage of a phenomenon called periapsis displacement — the gradual rotation of elliptical orbits of celestial bodies. In our solar system, the periapsis of Mercúrio, detected since the 19th century, illustrates this classic effect. The team analyzed 1,590 eclipsing binary stars observed continuously by TESS for at least two years.
Quando an outer planet exerts gravitational influence on a binary system, subtly alters the timing of eclipses — the precise instant at which the two stars obscure each other. With Medindo accurately analyzing the temporal variations of these eclipses, researchers identified gravitational signatures of planetary objects. The strategy revealed candidates that would have gone completely unnoticed by conventional techniques, significantly expanding the view on the real population of circumbinary planets.
Características and distribution of the 27 candidates
The masses of detected objects vary significantly, reflecting a diversity of planetary types:
- Mínimo: approximately 12 times the Earth’s mass
- Máximo: about 3,200 times the mass of Earth (approximately 10 times the mass of Júpiter)
- Distribuição: broad spectrum between worlds similar to Terra and gas giants
Additional Observações with the radial velocity method using ground-based telescopes will be needed to confirm these candidates. Essa technique detects planets indirectly by the wobble of host stars caused by planetary orbit, measuring color shifts in starlight as stars approach or move away from Terra.
Implicações for future planetary discoveries
Benjamin Montet, an associate professor at UNSW who is part of the research, highlights that abundant, long-term observational data from TESS made it possible to calculate extremely subtle effects. The satellite, originally designed to capture planetary transits, demonstrated an unexpected ability to reveal worlds whose transits would never be observed from Terra. Esse result shows that the conventional methodology underestimates the true population of exoplanets.
Planetas with diverse orbits and unfavorable geometries goes unnoticed, suggesting that the universe contains more planetary systems than previous surveys have revealed. Caso Future observations confirm the existence of these candidates, hoping for deeper understanding of planetary formation processes in Via Láctea. The discovery repositions how astronomers search for distant worlds and questions assumptions about what real fraction of exoplanetary systems humanity can currently map.