GCN Circular 46112
Subject
GRB 261029A: Glowbug gamma-ray detection
Event
Date
2026-10-30T14:45:24Z (18 hours ago)
From
C.C. Cheung at Naval Research Lab <Teddy.Cheung@nrl.navy.mil>
Via
Web form
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:
The Glowbug gamma-ray telescope [1,2,3], operating on the International Space Station, confirms the detection of GRB 261029A, which was detected by Fermi/GBM (GCN 46071, 46098), SVOM (GCN 46072, 46096), Fermi/LAT (GCN 46085), AstroSat/CZTI (GCN 46089), CALET (GCN 46095), NuSTAR (GCN 46100), and GECAM-B (GCN 46108).
Taking the CALET (GCN 46095) trigger time, T0 = 2026-10-29 01:27:33.19, Glowbug detects the bright multi-peaked emission from ~T0+2s to +10s. The detection occurred during a time of high background as Glowbug was in the northern radiation belt. Earlier emission may be present at lower significances.
The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
Glowbug 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.
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Woolf, R.S. et al. 2024, Proc. SPIE, 13151, id. 1315108
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