The probe Thess NASA has spotted two planets slightly larger than Earth orbiting a cold star. The system, named TOI-209it is found at 150 light years from uscould provide clues to the evolutionary process of super-Earths.
The study was conducted by the University of Liège and was published in Astronomy and Astrophysics. Tess’s goal is to track down, thanks to the transit method, exoplanets orbiting bright stars. To complete her task, Tess needs the support of the terrestrial telescopes, which allow to observe in detail the characteristics of the exoworlds.
Astronomers have discovered that the two planets, TOI-209 b And TOI-209 c, have resonant orbits and – at regular time intervals – always find themselves in the same configuration. This characteristic favors a strong gravitational interaction between the bodies, mutual attraction that delays, or sometimes accelerates, the passage in front of the star.
The researchers estimate that the radius of the planet b – closest to its star – is 1.2 times that of Earth. Its rocky composition and the presence of a thin atmosphere which protects it from the radiation of the celestial body make it very similar to our world.
The planet c instead it has a radius 1.9 times that of the Earth, a property that could place it in the category of “mini-Neptunes“, objects composed of a rocky and icy core surrounded by water-rich atmospheres, like Uranus and Neptune in our Solar System.
In the future, using more powerful telescopes and space observatories, we may be able to pinpoint the mass size of planets like these more clearly.
Top image: Artist’s impression of the TOI-209 system. Credits: Lionel J. Garcia / ULiège