GCN Circular 44435
Subject
GRB 260424B: AstroSat CZTI detection
Event
Date
2026-04-30T14:43:24Z (9 days ago)
From
Anuraag Arya at IIT Bombay <aryaanuraag910@gmail.com>
Via
Web form
M. Tembhurnikar (IUCAA), Harsha K. H. (IUCAA), S. Salunke (IUCAA), A. Goyal (IITB), A. Arya (IITB), U. Pathak (IITB), 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 a short GRB 260424B which was also detected by SVOM/GRM (Wang et al., GCN Circ. 44410), IPN triangulation (Kozyrev et al., GCN Circ. 44411), Konus-Wind (Ridnaia et al., 44416), and Glowbug (Cheung et al., 44418).
The source was clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2026-04-24 23:37:24.97 UTC. The measured peak count rate associated with the burst is 646 (+75, -82) counts/s above the background in the combined data of all quadrants, with a total of 685 (+158, -170) counts. The local mean background count rate was 1368 (+14, -15) counts/s. Due to the intrinsic 1 s binning of veto data, we cannot reliably estimate a T90 for our detection.
The source was also faintly detected in the CZT detectors in the 20-200 keV energy range.
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 data products like interactive and downloadable light curves for this GRB can be found at:
https://astrosat.iucaa.in/cift/cift_products/514769843.98/S514769843.98_details.html
CZTI GRB detections are reported regularly on the payload site at: http://astrosat.iucaa.in/czti/?q=grb