Statistical Analyses of White-Light Flares: Two Main Results about Flare Behaviour

Yohkoh Observations of White-light Flares

The Aspect Camera on the Soft X-ray Telescope (SXT) on Yohkoh has provided a unique database of white-light ares (WLFs). Coincident HXR and SXR observations give a unique opportunity to study the relationship between these diierent emissions and investigate the origins of the white-light emission. We have found that the spatial and temporal coincidence between impulsive white-light and HXR emis...

Two Results about Fixed Point of Multifunctions

Do All Flares Have White Light Emission?

High-cadence, multiwavelength optical observations of a solar active region (NOAA 10969), obtained with the Swedish Solar Telescope, are presented. Difference imaging of white light continuum data reveals a white light brightening, 2 min in duration, linked to a co-temporal and co-spatial C2.0 flare event. The flare kernel observed in the white light images has a diameter of 300 km, thus render...

On the origin of solar white-light flares

Using the Hα line intensity as a constraint, we study the role of a chromospheric condensation and the role of nonthermal effects in producing the continuum enhancement of white-light flares. Within an acceptable range of Hα line intensities and electron energy flux, it is shown that neither a chromospheric condensation nor non-thermal effects alone can directly explain the observed continuum e...

Magnetic reconnection mechanism for Type II white-light flares

Based on the concept that the heating source for Type II white-light flares (WLFs) may be located in the photosphere, we suggest that Type II WLF is reduced by magnetic reconnection in a weakly ionized plasma. A plasmoid may rise by magnetic buoyancy from the subphotosphere into a sunspot region and then expand to form a current sheet in which a type of resistive instability takes place. The ef...