TITLE: GCN CIRCULAR NUMBER: 22314 SUBJECT: Konus-Wind observation of GRB 180103A DATE: 18/01/10 16:49:22 GMT FROM: Dmitry Svinkin at Ioffe Institute D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik, M. Ulanov, A. Tsvetkova, A. Lysenko, A.Kozlova, and T. Cline on behalf of the Konus-Wind team, report: The bright long-duration GRB 180103A (Swift-BAT detection: Beardmore et al., GCN Circ. 22305; AstroSat-CZTI detection: Sharma et al., GCN Circ. 22310) triggered Konus-Wind at T0=4122.424 s UT (01:08:42.424). The burst light curve shows a multipeaked structure which starts at ~T0-19.5 s and has a total duration of ~237 s. The emission is seen up to ~10 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB180103_T04122/ As observed by Konus-Wind, the burst had a fluence of 3.41(-0.36,+0.33)x10^-4 erg/cm2, and a 64-ms peak flux, measured from T0+91.200 s, of 1.86(-0.27,+0.26)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+219.136 s) is best fit in the 20 keV - 20 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -1.31(-0.06,+0.06), the high energy photon index beta = -2.30(-0.30,+0.15), the peak energy Ep = 282(-33,+40) keV (chi2 = 81/96 dof). The spectrum near the maximum count rate (measured from T0+81.664 to T0+93.952 s) is best fit in the 20 keV - 20 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -1.00(-0.04,+0.04), the high energy photon index beta = -2.81(-0.99,+0.31), the peak energy Ep = 589(-48,+52) keV (chi2 = 107/97 dof). All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.