University of Liège researchers and CSIC – using observations from NASA's TESS telescope – present a study of a system slightly larger than two planets slightly larger than Earth orbiting a cold star in a synchronized dance. It is 150 light years away. The discovery is the result of a close collaboration between European and American universities, and was made possible by the US Space Mission Tess , which aims to find planets orbiting nearby bright stars." Tess conducts an all-sky survey using the transit method, i.e. star and observer. "Despite its power to detect new worlds, the Tess Mission needs support from ground-based telescopes to confirm the planetary nature of the detected signals," explains astrophysicist Francisco J. Pozuelos is an Astrophysicist, former member of the exotic laboratoryUniversity of Liège and now joining the Spanish National Research Council . The planets TOI-2096 B and TOI-2096 C have been observed with an international network of ground-based telescopes, allowing their confirmation and characterization. The majority of transits were obtained with telescopes from the Trappist and Speculoos projects, led by the University of Liège. Mathilde Timmermans, PhD student in the exotic laboratory at Uliège "By doing a thorough analysis of the data, we found that two planets are in resonance orbits for each orbit of the outer planet, the inner planet orbits the star twice," says the second author of the scientific paper. Therefore, their periods are approximately 3.12 days for Planet B and C. It is very close to being a multiple of each other, which is about 6.38 days for the planet. This is a very special configuration and causes a strong gravitational interaction between the planets. This interaction delays or accelerates the transit of planets in front of their stars and could lead to measurement of planetary masses using larger telescopes in the near future. " The researchers behind Discovery estimate Planet B—closest to its star—to be 1.2 times the radius of Earth, hence the name 'super-earth. Similarly, Planet C has a radius of 1.9 times the radius of Earth and 55% of Neptune, which can place the planet in the category of 'mini-neptunes', are planets consisting of a rocky and icy core surrounded by expanded hydrogen or Uranus in our solar system. and water-rich atmospheres such as Neptune. These sizes are very interesting because the number of planets with radii of 1.5 to 2.5 earth radii is smaller than theoretical models predict, making these planets rare. These planets are very important given their size, "Mathilde Timmermans" The formation of super-earths, super-earths, and mini-neptunes remains a mystery today. There are several formation models that attempt to explain this, but none fit the observations perfectly. TOI-2096 is the only system found to date to have a super-earth and a mini-neptune of such dimensions that the models contradict each other. In other words, TOI-2016 may be the system we are looking for to understand how these planetary systems are formed. " Francisco J. Pozuelos adds, "Moreover, these planets are among the best in their categories for studying their possible atmospheres." Thanks to the planets' relative sizes in relation to the host star and the star's luminosity, we find that this system is one of the best candidates for a detailed study of its atmosphere with the JWST space telescope. We hope to do this quickly by coordinating with other universities and research centres. These studies will help confirm the existence of a large or extensive atmosphere around planets B and C, thus giving us clues about their formation mechanisms. "