GCN Circular 43576
Subject
GRB 260127B: AstroSat CZTI detection
Event
Date
2026-01-31T05:11:40Z (2 days ago)
From
Anuraag Arya at IIT Bombay <aryaanuraag910@gmail.com>
Via
Web form
A. Arya (IITB), A. Goyal (IITB), M. Tembhurnikar (IUCAA), S. Salunke (IUCAA), Harsha K. H. (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 260127B which was also detected by Fermi GBM (Fermi GBM Team, GCN Circ. 43533), Swift BAT (Evans et al., GCN Circ. 43542), and Konus IPN (Ridnaia et al., GCN Circ. 43559).
The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve peaks at 2026-01-27 20:02:32.605 UTC. The measured peak count rate associated with the burst is 2558 (+901, -550) counts/s above the background in the combined data of all quadrants, with a total of 233 (+42, -31) counts. The local mean background count rate was 261 (+9, -32) counts/s. Using cumulative rates, we measure a T90 of 0.17 (+0.11, -0.03) s.
The source was also detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2026-01-27 20:02:32.292 UTC. The measured peak count rate associated with the burst is 602 (+68, -74) counts/s above the background in the combined data of all quadrants, with a total of 604 (+160, -170) counts. The local mean background count rate was 1239 (+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