2006ApJ...643..438C

Strong peaks in the emission measure-temperature (EM-T) distributions in the coronae of some binary stars are associated with the presence of hot (10⁷ K), dense (up to 10¹³/cm3) plasma. These peaks are very reminiscent of those predicted to arise in an impulsively heated solar corona. A coronal model comprised of many impulsively heated strands is adapted to stellar parameters. It is shown that the properties of the EM-T distribution can be accounted for in general terms provided the emission comes from many very small loops (length under 10³ km) with intense magnetic fields (1 kG) distributed across part of the surface of the star. The heating requires events that generally dissipate between 10²⁶ and 10^ 28^ ergs, which is in the range of solar microflares. This implies that such stars must be capable of generating regions of localized intense magnetic fields.