A warm terrestrial planet in orbit around Proxima Centaurii

An analysis of previously obtained observations and new Doppler data from instruments at the European Southern Observatory (ESO) reveals the presence of a small planet with a minimum mass of 1.3 Earth masses orbiting Proxima Centauri, the nearest star to the Sun. The planet, designated Proxima b, is in a close orbit with a period of approximately 11.2 days. Its equilibrium temperature is within the range where water could be liquid on its surface, although the current composition and existence of water on its surface are unknown because X-ray fluxes higher than those experienced by Earth might have produced a rather different atmosphere from our own over time. The discovery of a warm terrestrial planet orbiting a nearby star offers opportunities for further characterization including ― as technologies evolve ― by direct imaging and high-resolution spectroscopy.