[vsnet-grb-info 27799] GRB 210422B: Fermi GBM Final Localization

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  29902
SUBJECT: GRB 210422B: Fermi GBM Final Localization
DATE:    21/04/26 15:06:47 GMT
FROM:    Boyan A. Hristov at UAH  <bah0046 at uah.edu>

GRB 210422B: Fermi GBM Final Localization

The Fermi GBM Team reports the detection of a likely long GRB.

At 13:44:40.17 UT on 22 April 2021, the Fermi Gamma-Ray Burst Monitor
(GBM) triggered and located GRB 210422B (trigger 640791885 /
210422573).

This trigger coincides in time with INTEGRAL SPI-ACS trigger 9158.0
and CALET trigger 1303134201.

The on-ground calculated location, using the GBM trigger data, is
RA = 116.63, DEC = 24.71 (J2000 degrees, 7h 46m 31s, 24d 42' 36“),
with a statistical uncertainty radius of 2.11 degrees.

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

The GBM light curve consists of two peaks prominent in the range
10-300 keV.

A skymap can be found at:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210422573/quicklook/glg_skymap_all_bn210422573.png

HEALPix, including the estimated localization systematic:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210422573/quicklook/glg_healpix_all_bn210422573.fit

GBM light curve:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210422573/quicklook/glg_lc_medres34_bn210422573.gif