The October 28th 2003 X10 flare in AR10486 was clearly visible in GONG data. The maps show the changes in the Intensity (I), modulation (M) and magnetic field (B) measures of the Cerro Tololo instrument between 20.31 UT, before the flare, and 20.44 UT, near its peak. Observations were taken once per minute as part of the routine operation of the GONG network. The intensity is integrated over a 0.1 nm band pass centered on the 676.8 nm Ni I line. The modulation is the amplitude of a sine wave in wavelength with a frequency and phase that best fits the Ni I spectrum line. The modulation is normalized to that of full-disk-integrated sunlight.

The map covers an area approximately of 4 arcmin on a side (128 pixels). The lower panels show the evolution of each quantity over two hours at the pixel marked with a cross in the upper panels; the vertical dashed line indicates the 20.44 UT point.

For more details, see our SPD 2004 Poster .