{
  "circularId": 44478,
  "format": "text/plain",
  "subject": "GRB 260430B: Glowbug gamma-ray detection",
  "body": "C.C. Cheung, R. Woolf, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:\n\nThe Glowbug gamma-ray telescope [1,2,3], operating on the International Space Station, reports the detection of GRB 260430B, which was also detected by AstroSat/CZTI (GCN 44469) and SVOM/GRM (sb26043004).\n\nUsing an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2026-04-30 16:04:22.184 with a duration of 49.2 s and a total significance of about 113 sigma.  The light curve comprises a complex series of  peaks throughout the burst duration.\n\nThe analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.\n\nGlowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC.  It was launched on 2023 March 15 aboard the Department of Defense Space Test Program’s STP-H9 to the ISS and operated until 2024 April when it was put in safe storage on orbit. Glowbug was removed from storage and resumed operation on 2025 September 12.\n\n[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959\n[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O\n[3] Woolf, R.S. et al. 2024, Proc. SPIE, 13151, id. 1315108\n\nDistribution Statement A: Approved for public release.  Distribution is unlimited.",
  "submittedHow": "web",
  "submitter": "C.C. Cheung at Naval Research Lab <Teddy.Cheung@nrl.navy.mil>",
  "eventId": "GRB 260430B",
  "createdOn": 1777997199928
}