{
  "bibcode": "2025GCN.42507....1W",
  "circularId": 42507,
  "format": "text/plain",
  "subject": "GRB 251028B: Glowbug gamma-ray detection ",
  "body": "R. Woolf, C.C. Cheung, 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 251028B, which was also detected by Fermi GBM (GCN 42502) and CALET (GCN 42505). \n\nUsing an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2025-10-28 07:48:04.672 with a duration of 22.5 s and a total significance of about 30.5 sigma.  The light curve comprises two primary peaks.\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.",
  "createdOn": 1761675876398,
  "eventId": "GRB 251028B",
  "submittedHow": "web",
  "submitter": "richard.s.woolf.civ@us.navy.mil"
}