TITLE: GCN CIRCULAR NUMBER: 27715 SUBJECT: Konus-Wind observation of SGR 1935+2154 activity on 2020 May 10 DATE: 20/05/11 17:11:42 GMT FROM: Anna Ridnaia at Ioffe Institute A. Ridnaia, S. Golenetskii, R. Aptekar, D. Frederiks, M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, report: Two bright, short bursts from SGR 1935+2154 (IPN triangulation: Hurley et al., GCN Circ. 27714) triggered Konus-Wind at 22322.624 s UT (06:12:02.624) and 78677.28 s UT (21:51:17.280) on 2020 May 10. The first burst light curve shows a single, very bright pulse started with a sharp rise and then smoothly decayed to the background level. The second burst light curve shows two pulses separated by a ~0.15 s gap. Both bursts have a total duration of ~0.4 s. The emission is seen up to ~500 keV. As measured by KW, the burst fluences and peak fluxes are as follows: ------------------------------------------------------------------ # Date T0(KW) s UT Fl* PF** ------------------------------------------------------------------ 1 20200510 22322.624 s UT(06:12:02.624) 8.70 +/-0.22 38.9 +/-2.0 2 20200510 78677.280 s UT(21:51:17.280) 2.44 +/-0.10 17.8 +/-1.5 ------------------------------------------------------------------ * - Fluence (20-200 keV) in units of 1e-6 erg/cm2 ** - Peak Flux (20-200 keV) on 16-ms time scale in units of 1e-6 erg/cm2/s The time-averaged spectra of the bursts are well fit by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with the following parameters: ------------------------------------------------------------- # Tbeg-Tend alpha Ep(keV) chi2/dof ------------------------------------------------------------- 1 0 - 0.256 0.08(-0.23,+0.24) 47(-2,+2) 56/25 2 0 - 0.256 0.49(-0.65,+0.71) 37(-3,+2) 39/24 ------------------------------------------------------------- The Konus-Wind light curves of the bursts are available at http://www.ioffe.ru/LEA/SGRs/200510_T22322/ http://www.ioffe.ru/LEA/SGRs/200510_T78677/ All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.