Energetic flares on RS CVn stars

J.G. Doyle, P.B. Byrne, G.H.J. van den Oord
1989 International Astronomical Union Colloquium  
AbstractUltraviolet spectroscopic observations of the RS CVn star II Peg in February 1983 show evidence for flare activity in greatly enhanced chromospheric and transition region emission lines. The total radiative losses from the chromosphere and transition region (i.e. the temperature interval 4.0 ≤ log Te ≤ 5.4) during the flare is 3.1 1035 erg. Over the whole atmosphere (i.e. the temperature interval 4.0 ≤ log Te ≤ 8.0), we estimate total radiative losses of 2.4 1036 erg, (excluding
more » ... (excluding hydrogen line radiation). At flare peak, the flare radiated 1.5 1032 erg s–1. Adopting a two-ribbon flare model, where the filament is located between the two stars of the system, we can have 2039(l/R⊙) erg of magnetic energy available, where l is the filament length and we have taken a magnetic field strength of 1000G. Therefore, only a small fraction of this magnetic energy need be converted into heating of the flare plasma.
doi:10.1017/s0252921100153941 fatcat:caedk5hx6ncozasw3n2abwaceq