Proxima b: small planets around red dwarfs and the search for life beyond the Solar system
Queen Mary University of London
Aula Magna Enric Casassas
The existence of Proxima b -a possibly terrestrial planet in the habitable zone of the nearest star to the Sun- is a lucky concidence but not an event of cosmic fortune. Red dwarf stars that cannot be seen via naked eye are the most common stars in the Galaxy (about 70% of them) and detecting small, rocky, temperate and potentially habitable planets is way easier than around more massive stars like our Sun. I will put the discovery of Proxima b in the context of exoplanet detection and what we know in terms of the galactic abundance of planets around these stars. I will review the state of the art of the Doppler method in more detail, which is one of the two techniques leading to the discovery of the nearest red Earths. The smallness of the star also means that the planet-star contrast is better for potential follow-up studies such as atmospheric characterization and future attempts of directly imaging it. Looking into the future, the existence of terrestrial planets so close to our Sun has renewed the interest on advanced concepts to obtain direct images of them, and even sending interstellar probes within the next century.