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TITLE:   GCN CIRCULAR
NUMBER:  27692
SUBJECT: GRB 200506C: Fermi GBM Final Real-time Localization
DATE:    20/05/06 09:51:27 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM  <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 09:41:08 UT on 6 May 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200506C (trigger 610450873.980628 / 200506404).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 190.9, Dec = 40.2 (J2000 degrees, equivalent to J2000 12h 43m, 40d 12'), with a statistical uncertainty of 3.5 degrees.

The angle from the Fermi LAT boresight is 86.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200506404/quicklook/glg_skymap_all_bn200506404.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200506404/quicklook/glg_healpix_all_bn200506404.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200506404/quicklook/glg_lc_medres34_bn200506404.gif

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TITLE:   GCN CIRCULAR
NUMBER:  27697
SUBJECT: GRB 200506C: AstroSat CZTI detection
DATE:    20/05/06 19:41:20 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya@iucaa>

S. Gupta, V. Sharma, A. Vibhute and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed the detection of a long GRB 200506C, which was also detected by Fermi GBM (GCN #27692).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with the strongest peak at 2020-05-06 09:41:37.093 UT. The measured peak count rate associated with the burst is 307 +/- 25 cts/s above the background in the combined data of four quadrants, with a total of 9495 +/- 228 cts. The local mean background count rate was 547 +/- 1.0 cts/s. Using cumulative rates, we measure a T90 of 205.8 +/- 0.04 s. In preliminary analysis, we find that 756 Compton events are associated with this event.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.