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GCN Circular 32661

GRB221009A/Swift J1913.1+1946: Solar Orbiter STIX measurements
2022-10-10T15:23:32Z (2 years ago)
Hualin Xiao at FHNW <>
Hualin Xiao, S�m Krucker and Ryan Daniel on behalf of the STIX team report:

At 2020-10-09T13:16:56 UT (Solar Orbiter onboard time), STIX detected GRB221009A, when STIX was 1.22 AU from the earth.

The gamma-ray burst is clearly visible in the STIX quick-look light curves of five energy bands in the range between 4 -150 keV.

The initial pulse lasted about 10 seconds, followed by two bright pulses, lasting about 80 seconds.

The fourth pulse was detected at ~ 323 s after the initial pulse.

STIX recorded 185000 triggers from the burst in total.

STIX light curves can be found at:


Solar Orbiter location during the GRB:

The analysis results presented above are preliminary.  The science data will only be down-linked from the instrument in a month or two.  Detailed analysis of the event will be started after downloading the science data.

The Solar Orbiter (SolO) is a Sun-observing satellite developed by the European Space Agency, it was launched on 10th Feb. 2020.  It has a unique elliptical orbit around the sun, with distances varying from 0.3 - 1 AU. The Spectrometer Telescope for Imaging X-rays (STIX) is one of the ten instruments onboard the Solar Orbiter.  It measures X-rays emitted during solar flares in the energy range of 4 � 150 keV and takes X-ray images by using an indirect imaging technique, based on the Moir� effect.  Its detectors consist of thirty-two pixelated CdTe detectors with a total effective area of 6 cm^2.

More information about STIX can be found on the STIX data center website:
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