TITLE:   GCN CIRCULAR
NUMBER:  24649
SUBJECT: LIGO/Virgo S190521r:  No transient candidates from CALET observations
DATE:    19/05/22 03:04:49 GMT
FROM:    Yuta Kawakubo at Louisiana State U./CALET  <kawakubo1@lsu.edu>

S. Ozawa (Waseda U),  A. Yoshida, T. Sakamoto,
V. Pal'shin, S. Sugita (AGU), Y. Kawakubo (LSU),
K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
Y. Asaoka, S. Torii (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:

At the trigger time of the compact binary merger candidate S190521r,
T0 = 2019-05-21 07:43:59.463 UT (The LIGO Scientific Collaboration 
and Virgo Collaboration, GCN Circ. 24632), the CALET Gamma-ray 
Burst Monitor (CGBM) high voltages were off (from T0-6 min to 
T0+11 min).

The CALET Calorimeter (CAL) was operating in high energy trigger
mode at the trigger time of S190521r. Using the CAL data, we have
searched for gamma-ray events in the 10-100 GeV band from -60 
sec to +60 sec from the GW trigger time and found no candidates.
There is no significant overlap with the LVC location probability map.
The CAL FOV was centered at RA = 225.3 deg, Dec = 51.4 deg at T0.