TITLE: GCN CIRCULAR NUMBER: 35037 SUBJECT: GRB 231115A: a short hard GRB detected by IBAS, poistionally coincident with M82 DATE: 23/11/15 16:26:24 GMT FROM: Diego Gotz at CEA 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 short hard burst lasting about 150 ms has been detected by IBAS in the IBIS/ISGRI data at 15:36:22 UT of November 15, 2023. The refined coordinates (J2000) are: R.A.= 149.000901 [degrees] DEC.= 69.680130 [degrees] with an uncertainty of 2 arcmin (90% c.l.). We note that this position is consistent with the galaxy M82, so this event, which also triggered Fermi/GBM, may be due to a magnetar giant flare or to a nearby merger. So we encourage follow-up at other wavelengths. A plot of the light curve will be posted at http://ibas.iasf-milano.inaf.it/IBAS_Results.html