TITLE:   GCN CIRCULAR
NUMBER:  32674
SUBJECT: GRB 221006A: CALET Gamma-Ray Burst Monitor detection
DATE:    22/10/11 05:22:49 GMT
FROM:    Yuta Kawakubo at Louisiana State U./CALET  <kawakubo1@lsu.edu>

N. Cannady (GSFC/UMBC), A. Yoshida, T. Sakamoto, 
S. Sugita (AGU), Y. Kawakubo (LSU), K. Yamaoka (Nagoya U),
S. Nakahira (RIKEN), Y. Asaoka (ICRR), S. Torii, Y. Akaike,
K. Kobayashi (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U),
M. L. Cherry (LSU), S. Ricciarini (U of Florence),
P. S. Marrocchesi (U of Siena),
and the CALET collaboration:

The long GRB 221006A (MAXI/GSC detection: Mihara et al.,
GCN Circ. 32626) was marginally detected in the ground analysis
of the CALET Gamma-ray Burst Monitor (CGBM) data near the 
MAXI trigger time at 00:57:09 UTC on October 6, 2022.  
The burst signal was seen by only HXM detectors.

The burst light curve shows a faint signal which starts at T+0.8 sec,
peaks at T+9.8 sec and ends at T+26.8 sec.  The T90 and T50 
durations measured by the HXM2 data are 24.0 +/- 2.0 sec and 
14.0 +/- 2.0 sec (7-100 keV), respectively.  The highest significance
during the burst is 4.6 sigma at T+15.8 sec with HXM2 data in the 7 - 10 keV band.

The ground-processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1349052973/

The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at Waseda University.