Red dwarf. Satellite image of the red dwarf Proxima Centauri (centre). Explosive outbursts (flares, red) occur almost continually in the star's upper atmosphere. These flares are caused by the star's low mass, which is a tenth that of the Sun's. Nuclear fusion reactions that convert hydrogen to helium proceed very slowly in Proxima Centauri, creating a turbulent, convective motion throughout the star's interior. This motion stores up magnetic energy, which is then released explosively. Image taken on 7 May 2000 by the Advanced CCD Imaging Spectrometer (ACIS) aboard NASA's Chandra X-ray Observatory.