TITLE: GCN CIRCULAR NUMBER: 44681 SUBJECT: GRB 260225D: TERI Gamma-ray detection DATE: 26/05/21 14:06:05 GMT FROM: nicholasjkirschner@gmail.com Nicholas Kirschner (a), Daniel Shy (b), C.C. Cheung (b), Bernard Phlips (b), Michael Streicher (c), James Mason (c), Douglas M. Groves (c), Feng Zhang (c), and Willy Kaye (c) (a) National Research Council Research Associate resident at the U.S. Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 (b) U.S. Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 (c) 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 260225D, which was also detected by Glowbug (GCN 43856), Konus-Wind (Trig_Time 19:51:32.84), SVOM/GRM (GCN 43885), and GRID (GCN 43890). Using 1 Hz binning and adopting T0 = 2026-02-25T19:51:28.768Z, we observe two peaks at T0+1.375s and 2.625s and peak excess count rate of 108 and 149 counts per second (cps) above the 128 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 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 by the Office of Naval Research 6.1. [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/44681. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...