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1991 November 08 (M4.2)

A GOES M4.2 solar flare occurred on 1991 November 08 at an H-alpha location of S15W42 (heliographic coordinates). The soft X-ray flux began at 16:52 (60720 s), peaked at 17:12 (61920 s) and ended at 17:58 (64680 s) UT (GOES Geophysical Data Web Site). OSSE received a BATSE transient trigger at 61375 s and the four OSSE detectors slewed to the scan-angle position of the Sun. Two of the four detectors then initiated +/- 4.5 degree on-source-off-source viewing strategies. Because of the extreme DSA-angle of the Sun, however, the views of the top two detectors were obstructed and significant data were recorded by only the bottom two detectors.

Significant emmission of up to about 200 keV was observed during a ~140 s time interval (61400-61540 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 single power law with an index of about -3.7 was used to fit the data. The total fluence above 50 keV was 64.3 +/- 4.5 photons cm-2.

Figure 1

Figure 2

Last revised: 22 Jul 1999