GCN Circular 44487
Subject
GRB 260504B: AstroSat CZTI detection
Event
Date
2026-05-07T14:19:14Z (2 days ago)
From
Anuraag Arya at IIT Bombay <aryaanuraag910@gmail.com>
Via
Web form
A. Goyal (IITB), A. Arya (IITB), Harsha K. H. (IUCAA), S. Salunke (IUCAA), M. Tembhurnikar (IUCAA), G. Waratkar (Caltech/IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of GRB 260504B which is also detected by SVOM/GRM (Saccardi et al., GCN Circ. 44454), GECAM-B (Wang et al., GCN Circ. 44473), and Konus-Wind (Frederiks et. al., GCN Circ. 44474).
The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve peaks at 2026-05-04 09:31:16.450 UTC. The measured peak count rate associated with the burst is 1150 (+201, -203) counts/s above the background in the combined data of all four quadrants, with a total of 162 (+33, -36) counts. The local mean background count rate was 319 (+9, -11) counts/s. Using cumulative rates, we measure a T90 of 0.22 (+0.11, -0.07) s.
CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.
CZTI GRB detections are reported regularly on the payload site at:
http://astrosat.iucaa.in/czti/?q=grb