TITLE:   GCN CIRCULAR
NUMBER:  27934
SUBJECT: GRB 200612A: Fermi GBM detection
DATE:    20/06/13 20:50:23 GMT
FROM:    Christian Malacaria at NASA-MSFC/USRA  <cmalacaria@usra.edu>

C. Malacaria (NASA-MSFC/USRA), E. Burns (NASA-GSFC) and C. Meegan (UAH) 
report on behalf of the Fermi GBM Team:

At 04:49:38.68 UT on June 06 2020, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 200612A (trigger 613630183/200612201),
which was also detected by the Swift (Osborne et al. 2020, GCN 27921)
and Konus-Wind (Sonbas et al. 2020, GCN 27915; Svinkin et al. 2020, GCN 27922). 
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 50 degrees.

The GBM light curve shows multiple pulses with a 
duration (T90) of about 88 s (50-300 keV).
The GBM light curve also shows evidence of emission preceding the trigger time,
in agreement with the super-long GRB classification by Konus-Wind.

The time-averaged spectrum from T0-214 s to T0+89 s is best-fit
by a power-law with a photon index of -1.80 +/- 0.02.

The event fluence (10-1000 keV) in this time interval is
(4.187 +/- 0.109)E-05 erg/cm^2.
The 1-sec peak photon flux measured starting from T0+52 s 
in the 10-1000 keV band is 2.8 +/- 0.2 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/