TITLE:   GCN CIRCULAR
NUMBER:  33342
SUBJECT: GRB 230207B: CALET Gamma-Ray Burst Monitor detection
DATE:    23/02/18 08:37:02 GMT
FROM:    Yuta Kawakubo at Louisiana State U./CALET  <kawakubo1@lsu.edu>

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

The long GRB 230207B (AGILE detection: Casentini et al., 
GCN Circ 33296; Swift-BAT-GUANO detection: Raman et al.,
GCN Circ. 33298; Detection by GRBAlpha: Dafcikova et al.,
GCN Circ. 33303) triggered the CALET Gamma-ray
Burst Monitor (CGBM) at 04:40:43.38 UTC on 7 February 2023
(http://cgbm.calet.jp/cgbm_trigger/flight/1359779945/index.html).
The burst signal was seen by all CGBM detectors.

The burst light curve shows a single pulse that starts
at T+2.1 sec, peaks at T+5.2 sec, and ends at T+28.2 sec.
The T90 and T50 durations measured by the SGM data are 14.2 +/- 0.8 sec
and 4.7 +/- 0.1 sec (40-1000 keV), respectively.

The ground-processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1359779945/

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