GCN 44161: GRB 260330A: Glowbug gamma-ray detection
2026-03-30T21:27:51.443Z | rev 0
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 260330A, which was detected by Fermi/GBM (GCN 44151). The burst onset is at 2026-03-30 03:40:18.4 with a burst duration of ~16s. The lightcurve comprises an initial faint peak at ~T0+0.2s, followed by bright multi-peaked structures from ~T0+3s to +6s and ~T0+9s to +15.5s.
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. 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.
[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
Distribution Statement A: Approved for public release. Distribution is unlimited.
GCN 44151: GRB 260330A: Fermi GBM Final Real-time Localization
2026-03-30T03:48:27.940Z | rev 0
The Fermi GBM team reports the detection of a likely LONG GRB
At 03:40:19 UT on 30 Mar 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260330A (trigger 796534824.63566 / 260330153).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 93.6, Dec = -44.6 (J2000 degrees, equivalent to J2000 06h 14m, -44d 36'), with a statistical uncertainty of 2.8 degrees.
The angle from the Fermi LAT boresight is 63.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260330153/quicklook/glg_skymap_all_bn260330153.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260330153/quicklook/glg_healpix_all_bn260330153.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260330153/quicklook/glg_lc_medres34_bn260330153.gif