Astronomers have made a remarkable discovery using NASA's Transiting Exoplanet Survey Satellite (TESS): three Earth-sized exoplanets orbiting a close-knit pair of twin stars, a system known as TOI-2267. This finding is significant because it challenges prior theories that complex, stable planetary arrangements were unlikely to form or survive in binary star systems.
A Real-Life Tatooine System
The most evocative feature of this discovery is that the planets, orbiting a binary star system, would experience double sunsets, much like the fictional planet Tatooine in the Star Wars saga where Luke Skywalker watched two suns set.
The TOI-2267 system, located about 190 light-years from Earth, is a "compact binary," meaning the two stars orbit each other in close proximity.
The planetary architecture is unique: two of the Earth-sized planets transit one star, and the third transits its companion star. This makes TOI-2267 the first binary system known to host transiting planets around both of its stars.
Challenging Planet Formation Theories
This discovery breaks several records and provides a natural laboratory for studying planet formation under extreme conditions.
The TOI-2267 system is the most compact and coldest pair of stars with planets known.
The presence of these planets suggests that rocky worlds can emerge and survive in environments with complex gravitational dynamics, where their stability was previously thought to be compromised.
The research team used their detection software, SHERLOCK, on TESS data to get the first hints of these distant worlds, which then prompted follow-up observations using other specially adapted observatories.
Future Investigations
The system's surprising nature has profound implications for understanding the diversity of planetary architectures in our galaxy.
The James Webb Space Telescope (JWST) and the next generation of ground-based observatories are poised to investigate this system further.
Future observations aim to precisely measure the planets' masses, densities, and potentially their atmospheric chemistry. This will allow scientists to test the limits of current planet formation models in complex binary environments.
The team's research was published in the journal Astronomy & Astrophysics.