Back To OSSE Solar Flare Web Page

Get Acrobat       

Get Ghostscript

1991 June 03 (M1.5)

A GOES M1.5 solar flare occurred on 1991 June 03 at an H-alpha location of S13W52 (heliographic coordinates). The soft X-ray flux began at 20:49 (74940 s), peaked at 21:02 (75720 s) and ended at 21:12 (76320 s) UT (GOES Geophysical Data Website). OSSE received a BATSE transient trigger at 75449 s but the four OSSE detectors were already pointed at the scan-angle position of the Sun. Two of the four detectors then initiated +/- 4.5 degree on-source-off-source viewing strategies while the other two detectors remained pointed at the Sun. 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 emission of up to about 200 keV was observed during a ~280 s time interval (75437-75717 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 -5.2 was used to fit the data. The total fluence above 50 keV was 155.4 +/- 3.4 photons cm-2.

Figure 1

Figure 2

Last revised: 13 Jul 1999