TITLE:   GCN CIRCULAR
NUMBER:  35209
SUBJECT: GRB 231129A: INTEGRAL detection of a long GRB
DATE:    23/11/29 08:37:29 GMT
FROM:    Sandro Mereghetti at IASF-Milano/INAF <sandro.mereghetti@inaf.it>

S.Mereghetti (INAF, IASF-Milano), D.Gotz (CEA, Saclay), C.Ferrigno, E.Bozzo, V.Savchenko (ISDC, Versoix), L.Ducci (IAAT, Germany and ISDC, Versoix) and J.Borkowski (CAMK, Torun) report:

a gamma ray burst lasting about 150 s has been detected by IBAS in the  IBIS/ISGRI data at 05:05:59  UT of November 25, 2023.  The burst has also been detected by Swift (Gropp et al. GCN 35208)

The refined coordinates (J2000) are:
R.A.=  317.53411 deg
DEC.=  +41.51942 deg
with an uncertainty of 1.5  arcmin (90% c.l.).

The burst had a peak flux of about 0.5 ph/cm2/s (20-200 keV, 1-s integration time) and a fluence in the same energy range of about 6e-7 erg/cmq.

A plot of the light curve will  be posted at 
http://ibas.iasf-milano.inaf.it/IBAS_Results.html