TITLE: GCN CIRCULAR NUMBER: 44416 SUBJECT: Konus-Wind detection of GRB 260424B DATE: 26/04/28 15:28:08 GMT FROM: Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru> A. Ridnaia, D. Frederiks, A. Lysenko, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report: The short-duration GRB 260424B (SVOM/GRM detection: Wang et al., GCN Circ. 44410; IPN triangulation: Kozyrev et al., GCN Circ. 44411) triggered Konus-Wind at T0=85042.824 s UT (23:37:22.824). The burst light curve shows a multipeaked structure which starts at ~T0-0.1 s and has a total duration of ~0.6 s. The emission is seen up to ~3 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB260424_T85042/ As observed by Konus-Wind, the burst had a fluence of 3.02(-0.30,+0.33)x10^-6 erg/cm2, and a 16-ms peak flux, measured from T0+0.198 s, of 1.89(-0.35,+0.38)x10^-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the burst (measured from T0 to T0+0.256 s) is best fit in the 20 keV - 10 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -0.67(-0.14,+0.16) and Ep = 756(-131,+170) keV (chi2 = 25/41 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.0 (chi2 = 24/40 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/44416. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...