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Energetic flares on RS CVn stars

Published online by Cambridge University Press:  27 September 2017

J.G. Doyle ,
P.B. Byrne  and
G.H.J. van den Oord
J.G. Doyle
Affiliation:
Armagh Observatory, Armagh BT61 9DG, N. Ireland
P.B. Byrne
Affiliation:
Armagh Observatory, Armagh BT61 9DG, N. Ireland
G.H.J. van den Oord
Affiliation:
Dept. of Physics & Astronomy, University of Glasgow, Glasgow G12 8QQ, Scotland

Abstract

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Ultraviolet 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 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.

Type
Session I: Stellar Flares
Information
International Astronomical Union Colloquium , Volume 104 , Issue 2: Solar and Stellar Flares , 1989 , pp. 115 - 118
Copyright
Copyright © Kluwer 1989

References

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