{
  "bibcode": "2025GCN.41703....1T",
  "circularId": 41703,
  "createdOn": 1757004635528,
  "submitter": "Yuta Kawakubo at Aoyama Gakuin University <kawakubo@phys.aoyama.ac.jp>",
  "subject": "GRB 250902A: CALET Gamma-Ray Burst Monitor detection",
  "format": "text/plain",
  "body": "T. Tamura (Kanagawa U), A. Yoshida, T. Sakamoto, S. Sugita,\nY. Kawakubo (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA),\nY. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U), \nY. Shimizu (Kanagawa U), N. Cannady (GSFC/UMBC), M. L. Cherry (LSU),\nS. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena),\nand the CALET collaboration:\n\nThe long GRB 250902A (Fermi GBM Final Real-time Localization: \nFermi GBM team, GCN Circ. 41648;  SVOM/GRM observation: Wang et al.,\nGCN Circ. 41653; Fermi GBM Detection: Bala et al., GCN Circ. 41662;\nGECAM-B detection: Zheng et al., GCN Circ. 41687; VZLUSAT-2 detection:\nRipa et al., GCN Circ. 41701) triggered the CALET Gamma-ray Burst \nMonitor (CGBM) at 01:30:01.56 UTC on 2 September 2025\n(https://cgbm.calet.jp/cgbm_trigger/flight/1440811415/index.html).\nThe burst signal was seen by all CGBM detectors.  Because of a problem with the ground alert processing script, the GCN notice was not distributed automatically for this event.\n\nThe burst light curve shows a multi-peaked structure that starts\nat T-0.6 sec, peaks at T+2.9 sec, and ends at T+6.8 sec.\nThe T90 and T50 durations measured by the SGM data are 6.1 +/- 0.3 sec\nand 2.5 +/- 0.3 sec (40-1000 keV), respectively.\n\nThe ground-processed light curve is available at\n\nhttps://cgbm.calet.jp/cgbm_trigger/ground/1440811415/\n\nThe CALET data used in this analysis are provided by\nthe Waseda CALET Operation Center located at Waseda University.",
  "eventId": "GRB 250902A",
  "submittedHow": "web"
}