////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  29730
SUBJECT: GRB 210326A: Fermi GBM Final Localization
DATE:    21/03/26 22:39:00 GMT
FROM:    Joshua Wood at MSFC/Fermi-GBM  <joshua.r.wood@nasa.gov>

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

At 01:22:24.93 UT on 26 Mar 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 210326A (trigger 638414549.926002 / 210326057).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 58.0, Dec = +15.1 (J2000 degrees, equivalent to J2000 03h 52m, +15d 06'), with a statistical uncertainty of 39.2 degrees.

The angle from the Fermi LAT boresight is 69.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210326057/quicklook/glg_skymap_all_bn210326057.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210326057/quicklook/glg_healpix_all_bn210326057.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210326057/quicklook/glg_lc_medres34_bn210326057.gif


////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  29731
SUBJECT: GRB 210326A: Insight-HXMT/HE detection
DATE:    21/03/28 15:21:31 GMT
FROM:    Y Q Zhang at IHEP  <yqzhang@ihep.ac.cn>

Y. Q. Zhang, C. Cai, J. C. Liu, Q. Luo, S. Xiao, 
W. C. Xue, Q. B. Yi, C. Zheng，Y. Huang, C. K. Li, 
G. Li, X. B. Li, J. Y. Liao, X. Y. Song, S. L. Xiong, C. Z. Liu, 
X. F. Li, Z. W. Li, Z. Chang, A. M. Zhang, Y. F. Zhang, 
X. F. Lu, C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), 
T. P. Li (IHEP/THU), F. J. Lu, L. M. Song, 
M. Wu, Y. P. Xu, S. N. Zhang (IHEP), 
report on behalf of the Insight-HXMT team:

At 2021-03-26T01:22:24.93 (T0), Insight-HXMT/HE detected 
GRB 210326A (trigger ID: HEB210326057) in a routine search of the data, 
which also triggered Fermi/GBM (Fermi GBM team, GCN #29730).

The Insight-HXMT/HE light curve mainly consists of a single 
pulse with a duration (T90) of 0.17 s measured from T0-0.08 s. 
The 1-ms peak rate, measured from T0-0.08 s, is 5749 cnts/sec. 
The total counts from this burst is 733 counts. 
URL_LC: http://twiki.ihep.ac.cn/pub/HXMT/GRBList/HEB210326057_lc.jpg

All measurements above are made with the CsI detectors operating in the 
regular mode with the energy range of about 80-800 keV (deposited energy). 
Only gamma-rays with energy greater than about 200 keV can penetrate 
the spacecraft and leave signals in the CsI detectors installed inside 
of the telescope. 

Insight-HXMT is the first Chinese space X-ray telescope, which was 
funded jointly by the China National Space Administration (CNSA) and 
the Chinese Academy of Sciences (CAS). 
More information about it could be found at: 
http://www.hxmt.org.