The space weather forecast for Proxima Centauri B
Proxima Centauri, the closest star to the Earth (only 4.28 light-years away) is getting a lot of attention these days. It hosts a planet, Proxima Cen b, whose mass is about 1.3 Earth-mass (though it could be larger, depending on the angle at which we are viewing it). Moreover, Proxima Cen b orbits the star in its habitable zone. Proxima Cen itself is an M-dwarf star with a mass only about one-tenth the Sun's mass and a luminosity about one-thousandths of the Sun's; because the star is dim, the planet's habitable zone is twenty times closer to the star than the Earth's is to the Sun, and the planet orbits in 11.3 days. M dwarfs are the most abundant type of stars, and their small radii make them easier targets (relatively speaking) to spot transiting exoplanet signatures. Recent statistical estimates have concluded that half of M dwarf stars probably host...