TITLE: GCN CIRCULAR NUMBER: 44463 SUBJECT: Konus-Wind detection of GRB 260415C DATE: 26/05/04 20:18:18 GMT FROM: Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru> 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 260415C triggered Konus-Wind at T0=27659.163 s UT (07:40:59.163). The burst light curve shows a single pulse which starts at ~T0-2.5 s and has a total duration of ~11.3 s. The emission is seen up to 2 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB260415_T27659/ As observed by Konus-Wind, the burst had the total fluence of 3.64(-0.42,+0.54)x10^-6 erg/cm2, and the 64-ms peak flux, measured from T0-0.446 s, of 1.56(-0.41,+0.45)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 = -0.06(-0.45,+0.60), the high energy photon index beta = -2.91(-0.94,+0.36), the peak energy Ep = 105(-11,+12) keV (chi2 = 92/77 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/44463. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...