TITLE: GCN CIRCULAR NUMBER: 44166 SUBJECT: Konus-Wind detection of GRB 260316B DATE: 26/03/31 13:32:31 GMT FROM: Valentina Panteleeva at Ioffe Institute <panteleevav228@gmail.com> V. Panteleeva, 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 260316B (Fermi-GBM detection: The Fermi GBM team, GCN 44031; AstroSat CZTI detection: Harsha et al., GCN 44035, SVOM/GRM detection: Wang et al., GCN 44039, GECAM-B detection: Wang et al., GCN 44040, CALET-GBM detection: Tamura et al., GCN 44100, IPN triangulation: Kozyrev et al., GCN 44111) triggered Konus-Wind at T0=61972.457 s UT (17:12:52.457). The burst light curve shows a single pulse which starts at ~T0-0.9 s and has a total duration of ~2.5 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/GRB260316_T61972/ As observed by Konus-Wind, the burst had the total fluence of 2.66(-0.45,+0.56)x10^-6 erg/cm2, and the 64-ms peak flux, measured from T0+0.230 s, of 2.87(-0.74,+0.85)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the burst (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.24(-0.65,+0.76), the high energy photon index beta = -2.64(-7.36,+0.34), the peak energy Ep = 123(-22,+58) keV (chi2 = 64/77 dof). All the quoted errors are at the 68% confidence level. All the quoted values are preliminary. View this GCN Circular online at https://gcn.nasa.gov/circulars/44166. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...