TITLE: GCN CIRCULAR NUMBER: 42603 SUBJECT: GRB 251025C: TERI Gamma-ray detection DATE: 25/11/06 17:23:20 GMT FROM: Daniel Shy <danielshy@danielshy.com> Daniel Shy (a), C.C. Cheung (a), Bernard Phlips (a), Michael Streicher (b), James Mason (b), Douglas M. Groves (b), Feng Zhang (b), and Willy Kaye (b) (a) U.S. Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 (b) H3D, Inc., 812 Avis Dr., Ann Arbor, MI 48108, USA The cadmium zinc TElluride Radiation Imager (TERI) gamma-ray telescope [1], operating on the International Space Station, reports the detection of GRB 251025C, which was also detected by Fermi/GBM (GCN 42449), CALET (GCN 42467), AstroSat CZTI (GCN 42469), and Glowbug (GCN 42490). Using 1 Hz binning, we observe a single peak at 2025-10-25T23:08:40.79 with an excess of 27 counts per second (cps) above the 39 cps baseline rate observed in nearby off-source intervals. The analysis results presented here are preliminary and currently lack a detailed response function. TERI is an Office of Naval Research funded technology demonstrator for large-volume pixelated CdZnTe detectors developed, built, and operated by the U.S. Naval Research Laboratory (NRL) in conjunction with H3D, Inc. The pixelated CdZnTe detectors have an energy range of 40 keV to 3 MeV per pixel. It was launched on 2025 April 21 aboard the Department of Defense Space Test Program’s STP-H10 to the ISS. On the ISS, it is located on the SOX external payload facility on the Columbus module. Analysis of TERI data at NRL is supported under contract with NASA as correlative science for the Fermi Gamma-ray Space Telescope. [1] Shy, Daniel, et al. "Development of the cadmium zinc TElluride Radiation Imager." Journal of Astronomical Telescopes, Instruments, and Systems 10.4 (2024): 044009-044009 (arXiv:2408.04559). Distribution Statement A: Approved for public release. Distribution is unlimited. View this GCN Circular online at https://gcn.nasa.gov/circulars/42603. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...