Abstract
Three of the nine white-light flares thus far discovered in the Yohkoh
white-light data were also
observed at
the Nobeyama Radio Observatory at its 80 GHz polarimeter.
Each of the three flares
was relatively close to the center of the Sun and had an H_alpha
importance of 2B-3B, but the
X-ray classes were quite different: the flares of 27 Oct. 1991, 15 Nov.
1991, and 14 Feb. 1992 had
GOES X-ray magnitudes of X6.1, X1.5, and M7.0 respectively. We have
analyzed the
characteristics of these flares at white-light, X-ray and radio
wavelengths in order to find clues
for the emission mechanisms of the white-light and millimeter-wave
continuum. Each of these
three flares had both impulsve and gradual optical emissions. Using the
Yohkoh soft X-ray
images we associate the gradual component of white-light emission in
these flares with compact
high-temperature loops. We speculate that the white light itself comes
from fine structures
embedded in these loops, at densities greater than normal photospheric
densities.