GCN Circular 46129
GRB 261029C: AstroSat CZTI detection of a short burst
From: ABHINAV GOYAL at Indian Institute of Technology Bombay
Issued: 2026-11-02 12:22 UTC
Type: GRB, Gamma-ray Transient, X-ray Transient
Why this event is posted: every one of the gamma-ray bursts is posted.

Harsha K. H. (IUCAA), S. Salunke (IUCAA), S. Puri (IITB), A. Goyal (IITB), A. Arya (IITB), G. Waratkar (Caltech/IITB), V. Bhalerao (IITB), A. Vibhute (IUCAA), 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 261029C which was also detected by KONUS-Wind (via IPN notices) and SVOM/GRM (via notices).

The source was detected in the CZT detectors in the 20-200 keV energy range. The light curve peaks at 2026-10-29 23:38:36.92 UTC. The measured peak count rate associated with the burst is 2429 (+322, -332) counts/s above the background in the combined data of all four quadrants, with a total of 351 (+46, -51) counts. The local mean background count rate was 304 (+11, -15) counts/s. We measure a T90 of 0.17 (+0.06, -0.03) s from the cumulative CZT light curve.

The source was also detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

CZTI data products like interactive and downloadable light curves for this GRB can be found at:
https://astrosat.iucaa.in/cift/cift_products/ET20261029T233836/ET20261029T233836_details.html

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

Every one of the gamma-ray bursts GCN reports is posted here.
Relayed automatically from NASA's General Coordinates Network.