TITLE: GCN CIRCULAR NUMBER: 25844 SUBJECT: LIGO/Virgo S190924h: Not observable by CALET DATE: 19/09/25 04:15:11 GMT FROM: Yuta Kawakubo at Louisiana State U./CALET T. Sakamoto, A. Yoshida, 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 S190924h, T0 = 2019-09-24 02:18:46.847 UT (The LIGO Scientific Collaboration and Virgo Collaboration, GCN Circ. 25829), the CALET Gamma-ray Burst Monitor (CGBM) high voltages were off (from T0-1 min to T0+16 min). The CALET Calorimeter (CAL) was operating in the high energy trigger mode at the trigger time of S190924h. 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 high probability localization region. The CAL FOV was centered at RA=273.4 deg, Dec=40.2 deg at T0.