A new super-Earth, named HD 20794 d, has been discovered orbiting a Sun-like star in the habitable zone, a region where liquid water could exist. The discovery, made by an international team including the University of Geneva (UNIGE) and the NCCR PlanetS consortium, was announced in the journal Astronomy & Astrophysics.
HD 20794 d is located 19.7 light-years from Earth and is a rocky planet larger than our own. It orbits a G-type star, similar to our Sun, in a highly elliptical orbit. This means that the planet periodically passes through the habitable zone, where temperatures could support liquid water on its surface.
The discovery was made after more than 20 years of observations using advanced telescopes, including ESPRESSO and HARPS. The team used a sophisticated algorithm called YARARA to eliminate noise and confirm the planet's presence with high precision.
The proximity of the HD 20794 system to Earth makes it a prime target for future observations, such as those planned with the ANDES spectrograph on the European Southern Observatory's Extremely Large Telescope (ELT). Further studies will be needed to determine if the planet can support life, requiring collaboration between astronomers, chemists, and biologists.