A temperate rocky super-Earth transiting a nearby cool star

Understand

M dwarf stars, which have masses less than 60 per cent that of the Sun, make up 75 per cent of the population of the stars in the Galaxy [1].

• The atmospheres of orbiting Earth-sized planets are observationally accessible via transmission spectroscopy when the planets pass in front of these stars [2,3].
• Statistical results suggest that the nearest transiting Earth-sized planet in the liquid-water, habitable zone of an M dwarf star is probably around 10.5 parsecs away [4].
• A temperate planet has been discovered orbiting Proxima Centauri, the closest M dwarf [5], but it probably does not transit and its true mass is unknown.