IUE observations of GL 644 AB (=Wolf 630) in the wavelength region 1150-1950 A, in June 1981.

Abstract

IUE short wavelength observations of the flare star Gl 644, obtained in June 1981 are presented. A flare was detected in one of the spectra as a strong increase in C IV, He II, and continuum fluxes. The electron density of the flaring plasma, determined using line ratio techniques, is 4 x 10 to the 10th/cu cm, which is an increase by a factor of 2.7 above the quiescent. The radiative losses of the flare are at least 1.3 x 10 to the 32nd erg and 4.0 x 10 to the 33rd erg over the temperature range log Te between 4.3 and 5.4 and log Te between 4.0 and 8.0, respectively. This compares with continuum losses of 8.1 x 10 to the 31st erg over the wavelength region 1250-1950 A.