Konus-Wind detection of GRB 210124B

The short-duration, bright GRB 210124B (Insight-HXMT/HE detection: Liu et al., GCN Circ. 29353; IPN triangulatuion: Hurley et al., GCN Circ. 29355;) triggered Konus-Wind at T0=48224.368 s UT (13:23:44.368). The burst light curve shows a multipeaked structure which starts at ~T0-20 ms and ends at ~T0+40 ms, followed by a weaker emission seen up to ~T0+170 ms. The total burst duration is ~0.2 s. The emission is seen up to ~6 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB210124_T48224 As observed by Konus-Wind, the burst had a fluence of 3.03(-0.71,+0.86)x10^-6 erg/cm2, and a 16-ms peak flux, measured from T0-0.006 s, of 6.16(-2.15,+2.54)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+0.064 s) is best fit in the 20 keV - 6 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -0.93(-0.20,+0.25) and Ep = 1544(-642,+1186) keV (chi2 = 33/20 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -1.5 (chi2 = 33/19 dof). All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.