TITLE: GCN CIRCULAR NUMBER: 40977 SUBJECT: Konus-Wind detection of GRB 250703A DATE: 25/07/05 14:50:15 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 250703A (Fermi-GBM detection: The Fermi GBM team, GCN 40909; IPN localization Kozyrev et al., GCN 40976) triggered Konus-Wind (KW) at T0=32851.983 s UT (09:07:31.983). The burst light curve shows a single multi-peaked emission pulse with a total duration of ~4.5 s. The emission is seen up to ~5 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB250703_T32851/ As observed by Konus-Wind, the burst had a fluence of (5.86 ± 0.66)x10^-6 erg/cm^2 and a 64-ms peak energy flux, measured from T0 + 0.960 s, of (3.81 ± 0.43)x10^-6 erg/cm^2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 15 MeV range by a GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.36 (-0.22,+0.28), the high energy photon index beta = -2.76 (-0.49,+0.27), the peak energy Ep = 147(-15,+15) keV, chi2 = 84/94 dof. All the quoted errors are estimated at the 68% confidence level. All the presented results are preliminary. View this GCN Circular online at https://gcn.nasa.gov/circulars/40977. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...