A CME Model for the 1992 July 15 AU Mic Flare Observed by EUVE

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Session 15 -- Flare and Active Stars
Display presentation, Wednesday, January 12, 9:30-6:45, Salons I/II Room (Crystal Gateway)

[15.02] A CME Model for the 1992 July 15 AU Mic Flare Observed by EUVE

S.L. Cully, G.H. Fisher, O.H.W. Siegmund (Space Science Laboratory University of California, Berkeley)

The flare star AU Mic was observed by the EUVE Deep Survey Instrument on 1992 July 14-18. A large flare was detected in the Deep Survey Lexan/Boron (65 - 190 A) band and the SW (70 - 190 A) and MW (140 - 380 A) spectrometers. The flare consisted of a sharp impulsive peak lasting approximately 2 hours followed by a decaying tail lasting about a day. We present a simple, dynamical model which is consistent with the the DS light curve and reproduces the strongest spectral lines in the publicly released EUVE archive spectra of this observation. In this model, we assume the long decay time is due to an ejected, magnetically confined, low beta, plasmoid expanding self similarly in the stellar wind. Initial estimates of the mass of the plasmoid indicate that these types of ejections may make a significant contribution to the mass balance of the ISM and may be responsible for a large part of the angular momentum evolution of active, late type stars.

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