GCN Circular 34104

S. Nakahira (JAXA), A. Yoshida, T. Sakamoto, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), Y. Asaoka (ICRR),
S. Torii, 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 230623B (GECAM trigger 195; Swift/BAT-GUANO 
detection: Ronchini et al.,GCN Circ. 34076) triggered the CALET 
Gamma-ray Burst Monitor (CGBM) at 21:22:37.02 UTC on 23 
June 2023
(http://cgbm.calet.jp/cgbm_trigger/flight/1371590547/index.html).
The burst signal was seen by all CGBM detectors.  No real-time 
CGBM GCN notice was distributed about this trigger because
the real-time communication from the ISS was off (loss of signal).

The burst light curve shows a multi-peaked structure that starts
at T-3.2 sec, peaks at T+13.9 sec, and ends at T+20.4 sec.
The T90 and T50 durations measured by the SGM data are 21.4 +/- 1.5 sec
and 13.4 +/- 0.6 sec (40-1000 keV), respectively.

The ground-processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1371590547/

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