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2000 January 12 (M2.8)

A GOES M2.8 solar flare occurred on 2000 January 12 at an H-alpha location of N13E81 (heliographic coordinates). The soft X-ray flux began at 1:32 (5520 s), peaked at 1:38 (5880 s) and ended at 1:43 (6180 s) UT (GOES Geophysical Data Web Site). OSSE received a BATSE transient trigger at 5593 s and the four OSSE detectors slewed to the scan-angle position of the Sun and initiated +/- 4.5 degree on-source-off-source viewing strategies.

Significant emission to above 3 MeV was observed during a ~254 s time interval (5628-5882 s). Count rate time profiles in various energy windows at a temporal resolution of ~8 s are shown in Figure 1. A representative count spectrum is shown in Figure 2. A broken power law which hardened from an index of 4.39 +/- 0.03 below a break energy of ~260 keV to 3.05 +/- 0.32 above the break energy fit the data better than a single power law. The total fluence above 50 keV was 2145 +/- 25 photons cm-2.

Figure 1

Figure 2

Last revised: 02 Aug 1999