{
  "bibcode": "2026GCN.44989....1T",
  "format": "text/plain",
  "subject": "GRB 260617A: CALET Gamma-Ray Burst Monitor detection",
  "submitter": "Yuta Kawakubo at Aoyama Gakuin University <kawakubo@phys.aoyama.ac.jp>",
  "circularId": 44989,
  "createdOn": 1781857200708,
  "eventId": "GRB 260617A",
  "submittedHow": "web",
  "body": "S. Torii (Waseda U), A. Yoshida, T. Sakamoto, S. Sugita, Y. Kawakubo (AGU),\nK. Yamaoka (Nagoya U), S. Nakahira (JAXA), Y. Asaoka (ICRR), Y. Akaike, \nK. Kobayashi (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U),\nN. Cannady (GSFC), M. L. Cherry (LSU), S. Ricciarini (U of Florence),\nP. S. Marrocchesi (U of Siena),\nand the CALET collaboration:\n\nThe CALET Gamma-ray Burst Monitor (CGBM) detected GRB 260617A\nat 21:36:43.92 UTC on 17 June 2026 (trigger #1465767277;\nhttps://cgbm.calet.jp/cgbm_trigger/flight/1465767277/index.html).\n\nNo real-time CGBM GCN Notice was distributed about this trigger because \nthe real-time communication from the ISS was off (loss of signal).\n\nThis event was also reported by Fermi GBM (The Fermi GBM team et al., GCN #44969;\nGodwin et al., GCN #44972), Konus-Wind and Mars-Odyssey (IPN triangulation: Kozyrev et al., GCN #44982).\n\nThe burst signal was seen by HXM1 and SGM.  The burst light curve shows a short pulse from T-0.25 s to T-0.15 s.\nThe T90 and T50 durations measured with the SGM data are 0.09 +/- 0.02 s\nand 0.05 +/- 0.01 s in the 40-1000 keV band, respectively.\n\nThe ground-processed light curve is available at:\nhttps://cgbm.calet.jp/cgbm_trigger/ground/1465767277/\n\nThe CALET data used in this analysis were provided by\nthe Waseda CALET Operation Center located at Waseda University."
}