G-type star tagged posts

Thirty years after the discovery of the first exoplanet, astronomers have detected more than 7,000 of them in our galaxy. But there are still billions more to be discovered. At the same time, exoplanetologists have begun to take an interest in their characteristics, with the aim of finding life elsewhere in the universe. This is the background to the discovery of super-Earth HD 20794 d by an international team including the University of Geneva (UNIGE) and the NCCR PlanetS.

The new planet lies in an eccentric orbit, so that it oscillates in and out of its star’s habitable zone. This discovery is the fruit of 20 years of observations using the best telescopes in the world. The results are published in the journal Astronomy & Astrophysics.

‘”Are we alone i...

Currently, 5,788 exoplanets have been confirmed in 4,326 star systems, while thousands more candidates await confirmation. So far, the vast majority of these planets have been gas giants (3,826) or Super-Earths (1,735), while only 210 have been “Earth-like”—meaning rocky planets similar in size and mass to Earth.

What’s more, the majority of these planets have been discovered orbiting within M-type (red dwarf) star systems, while only a few have been found orbiting sun-like stars. Nevertheless, no Earth-like planets orbiting within a sun-like star’s habitable zone (HZ) have been discovered so far.

This is largely due to the limitations of existing observatories, which have been unable to resolve Earth-size...