TITLE:   GCN CIRCULAR
NUMBER:  27314
SUBJECT: GRB 200303A: Fermi GBM observation
DATE:    20/03/04 10:26:57 GMT
FROM:    Elisabetta Bissaldi at INFN,Bari  <elisabetta.bissaldi@ba.infn.it>

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


"At 02:34:23.85 UT on 03 March 2020,
the Fermi Gamma-Ray Burst Monitor (GBM) triggered
and located GRB 200303A (trigger 604895668 / 200303107),
which was also detected by the Swift/BAT and Swift/XRT
(Cenko et al. 2020, GCN 27297, Goad et al. 2020, GCN 27300).
The Fermi GBM Final Real-time Localization (GCN 27294)
is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time
is 106 degrees.

The GBM light curve shows a complex structure
with a duration (T90) of about 82 s (50-300 keV).
The time-averaged spectrum from T0-2.8 s to T0+95.7 s is
best fit by a Band function with Epeak = 151 +/- 18 keV,
alpha = -1.26 +/- 0.05, and beta = -2.14 +/- 0.10.

The event fluence (10-1000 keV) in this time interval is
(3.23 +/- 0.08)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+35.1 s in the 10-1000 keV band
is 9.2 +/- 0.4 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/"