TITLE:   GCN CIRCULAR
NUMBER:  33235
SUBJECT: GRB 230128A: AstroSat CZTI detection
DATE:    23/01/30 09:22:07 GMT
FROM:    Gaurav Waratkar at IIT,Bombay  <gauravwaratkar@iitb.ac.in>

P K. Navaneeth (IUCAA), R. Gopalakrishnan (IUCAA), G. Waratkar (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 long GRB230128A which was 
also detected by Fermi GBM (GCN Circ. 33231).

It was clearly detected in the CsI anticoincidence (Veto) detector in 
the 100-500 keV energy range. The light curve peaks at 2023-01-28 
22:48:33.09 UTC. The measured peak count rate is 669 (+68, -52) counts/s 
above the background in the combined Veto data of all quadrants, with a 
total of 9446 (+1558, -2165) counts. The local mean background count 
rate was 2912 (+3, -5) counts/s. We measure a T90 of 53 (+12, -16) s 
from the cumulative Veto light curve.

CZTI GRB detections are reported regularly on the payload site at 
http://astrosat.iucaa.in/czti/?q=grb. 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.