TITLE:   GCN CIRCULAR
NUMBER:  30340
SUBJECT: GRB 210626A: Fermi GBM observation
DATE:    21/06/28 15:25:08 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

A. von Kienlin (MPE) and C. Meegan (UAH) 
report on behalf of the Fermi GBM Team:

"At 08:16:15.99 UT on 26 June 2021, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 210626A (trigger 646388180 / 210626345), which was
also 
detected by the Swift/BAT-GUANO (Tohuvavohu et al. 2021, GCN 30325).
The Fermi GBM Final Real-time Localization is consistent with the Swift
position.

The angle from the Fermi LAT boresight at the GBM trigger time is 73
degrees.

The GBM light curve shows a singel pulse with a duration (T90) of 
about 34 s (50-300 keV). The time-averaged spectrum from T0-5.632 s 
to T0+29.184 s is best fit by a Band function with Epeak= 86 +/- 18 keV, 
alpha = -1.21 +/- 0.16 and beta = -2.25 +/- 0.24

The event fluence (10-1000 keV) in this time interval is
(5.1 +/- 0.4)E-06 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+5.696 s in the 10-1000 keV band
is 3.40 +/- 0.24 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/"