Pesquisadores of Universidade of Nova Gales of Sul identified 27 new circumbinary planet candidates by analyzing data from NASA’s TESS satellite. The discovery, published in the journal Monthly Notices of the Royal Astronomical Society, used an innovative method based on the displacement of periapsis in eclipsing binary stars, bypassing limitations of the conventional transit method.
Esses candidate planets orbit binary star systems — configurations where two suns gravitate around each other. The research led by Margo Thornton represents a significant advance in detecting worlds whose orbital geometry would make them invisible to ground-based telescopes using traditional techniques.
Limitações of the transit method and the need for innovation
The transit method, the dominant technique for discovering exoplanets, identifies planets by the slight dimming they cause as they pass in front of their stars. Funciona accurately when the planet’s orbital plane is aligned perpendicularly with the Earth’s perspective. Porém, for circumbinary planets, this geometric 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. Isso means that an entire class of circumbinary planets — those with highly inclined orbits — remained invisible to observers. The team recognized that previous observational data reflected an intrinsic bias: only planets with specific orientations were found.
Thornton summarizes the study’s motivation: Previous observational data depended exclusively on the orientation of the planet’s orbit, preventing full understanding of how worlds arise in binary systems.
Periapsis Deslocamento as a detection tool
The new method took advantage of a phenomenon called periapsis displacement — the gradual rotation of elliptical orbits of celestial bodies. In solar systems, 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.
Medindo accurately analyzed the temporal variations of these eclipses, researchers identified gravitational signatures of planetary objects. The strategy revealed candidates that would go completely unnoticed by conventional transit techniques, expanding the view on the real population of circumbinary planets.
Características of the 27 discovered candidates
The masses of detected objects vary significantly:
- 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
Nenhuma definitive confirmation has been achieved. Additional Observações with the radial velocity method using ground-based telescopes will be needed. Essa technique detects planets indirectly by the wobble of host stars caused by planetary orbit, by measuring color shifts in starlight that occur as stars move closer to or away from Terra.
Significado 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 is particularly notable because it highlights that 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 humans can currently map.