New planet detected around star closest to the Sun

The newly discovered planet, named Proxima d, orbits Proxima Centauri at a distance of about four million kilometres, less than a tenth of Mercury’s distance from the Sun. It orbits between the star and the habitable zone — the area around a star where liquid water can exist at the surface of a planet — and takes just five days to complete one orbit around Proxima Centauri.

The star is already known to host two other planets: Proxima b, a planet with a mass comparable to that of Earth that orbits the star every 11 days and is within the habitable zone, and candidate Proxima c, which is on a longer five-year orbit around the star.

Proxima Centauri is a small star, with seemingly a decent collection of planets. This *may* be evidence that planets should be pretty common. And while there is a roughly Earth-sized planet within the habitable zone of Proxima, it is very unlikely to be congenial to life. Proxima, like many red dwarfs, is a flare star. And while the Sun also spits out some substantial flares from time to time, with these itty-bitty stars, the habitable zone is *real* *close* to the star. The flares that on the sun  would be barely detectable on Earth, would quickly strip the atmosphere from an Earthlike planet orbiting a red dwarf.