TITLE: GCN CIRCULAR NUMBER: 41013 SUBJECT: GRB 250706C: Konus-Wind detection of a very bright GRB ~1200 s before GRB 250706B DATE: 25/07/07 17:17:34 GMT FROM: Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru> D. Frederiks, A.Lysenko, A. Ridnaia, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report: The long-duration GRB 250706C triggered Konus-Wind (KW) at T0=60322.626 s UT (16:45:22.626). The burst light curve shows a very bright, multi-peaked emission pulse with the duration of ~50 s (20-1500 keV). This pulse is followed by a weaker, smoothly decaying emission tail, visible at lower energies (20-100 keV) up to the end of the KW triggered data record (~T0+250 s). A preliminary plot of the KW light curve is available at http://www.ioffe.ru/LEA/GRBs/GRB250706_T60322/KW20250706_60322_BG.png The KW ecliptic latitude response suggest the source location in the southern ecliptic hemisphere, at moderate-to-high ecliptic latitude. We note that the KW trigger time is ~1200 s before SVOM/ECLAIRs trigger on GRB 250706B at 2025-07-06T17:05:23 (Palmerio et al., GCN 40989), in the [5-20] keV energy band, and localized to R.A., Dec. 41.1337, -50.1172 deg, which is consistent with the KW ecliptic latitude response. This may suggest that the KW GRB 250706C is an initial, prompt emission episode of GRB 250706B. The KW analysis of GRB 250706C is ongoing and its detailed results will be reported in a separate GCN. View this GCN Circular online at https://gcn.nasa.gov/circulars/41013. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...