MULTI-WAVELENGTH OBSERVATIONS OF A LARGE SOLAR FLARE

Анотація

We present the results of the multi-
wavelength study of the two-ribbon solar flare on July
19, 2000 in the active region NOAA 9087. The evo-
lution and morphological properties of the flare pro-
ductive active region have been analyzed. The active
region was growing rapidly and showed a complex mul-
tipolar magnetic field configuration. It was large, pro-
ducing many events, including the flare under consid-
eration. The 3N/M6.4 two-ribbon flare was a promi-
nent, long duration event in the active region evolution.
According to Solar Geophysical Data (SGD) the flare
lasted 2.5 hours. The flare energy release took place in
many sites of the active region.
We used combination of data from space and ground
based observatories for study. The hard X-ray (HXR)
and soft X-ray (SXR) data were obtained at the
Yohkoh Telescopes (HXT and SXT) and Geostationary
Operational Environmental Satellite (GOES). The full-
disk magnetograms and EUV-images were provided
by the Solar and Heliospheric Observatory (SOHO)
Michelson Doppler Imager (MDI) and Extreme ultra-
violet Imaging Telescope (EIT). We used the H α filter-
grams from the Meudon spectroheliograph and white
light images of Big Bear Solar Observatory (BBSO).
All the data show continuously evolving SXR, EUV
and H α features during the flare. The HXR and the
type III radio bursts were observed at the flare onset.
The first H α flare kernels and the surge, connected
with the filament eruption, were initiated near a large
positive-polarity sunspot. The main bright kernels of
the flare occurred at the centre of the active region
near magnetic neutral line, after that the flare ribbons
appeared along it. It was found that HXR coronal
source was located along a magnetic polarity inversion
line of the active region. EUV loop structures indicate
the observational evidence of a magnetic reconnection
during the main phase of the flare.