Free Astronomy Magazine March-April 2022

20 MARCH-APRIL 2022 ASTRO PUBLISHING O ne of the most studied stars in the entire sky is Proxima Centauri, the closest star to our Solar System, located at a dis- tance of “just” 4.24 light-years. We know that it is a red dwarf (spectral class M5.5V) with a mass and a diam- eter almost ten times smaller than those of the Sun. Despite its tiny size, Proxima Centauri shows much more intense magnetic activity than our star, which manifests itself mainly through the recurrent emis- sion of white light flares. For our Sun, this highly energetic phenome- non occurs a few times per century. In the case of Proxima Centauri, at least a couple of white light flares occur each day, a quantity that con- siderably complicates photometric and spectroscopic studies of the star. This is a feature that almost all red Proxima b, a truly elusive planet by Michele Ferrara revised by Damian G. Allis NASA Solar System Ambassador A hypothetical landscape for the planet Proxima b, dominated by the looming presence of its star, Proxima Centauri. Like many red dwarfs, Proxima Centauri also mani- fests its magnetic activity in the form of frequent flares that flood the surrounding planets with deadly radiation. [NASA/Ames Research Center/Daniel Rutter]