GCN Circular 43680
Subject
GRB 260207B: AstroSat CZTI detection
Event
Date
2026-02-10T11:47:42Z (16 hours ago)
From
Anuraag Arya at IIT Bombay <aryaanuraag910@gmail.com>
Via
Web form
A. Goyal (IITB), A. Arya (IITB), S. Salunke (IUCAA), Harsha K. H. (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 a short GRB 260207B which was also detected by Fermi GBM (Fermi GBM Team, GCN Circ. 43629) and GECAM (Zao et. al., GCN Circ. 43644).
The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve peaks at 2026-02-07 13:12:07 UTC. The measured peak count rate associated with the burst is 1402 (+767, -219) counts/s above the background in the combined data of all four quadrants, with a total of 82 (+26, -21) counts. The local mean background count rate was 269 (+12, -45) counts/s. Using cumulative rates, we measure a T90 of 0.09 (+0.06, -0.03) s. We only observed the main emission (ME) part of the burst.
The source was also detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2026-02-07 13:12:07 UTC. The measured peak count rate associated with the burst is 446 (+68, -75) counts/s above the background in the combined data of all quadrants, with a total of 630 (+143, -162) counts. The local mean background count rate was 1340 (+7, -8) counts/s. Due to the intrinsic 1 s binning of veto data, we cannot reliably estimate a T90 for our detection.
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