TITLE: GCN CIRCULAR NUMBER: 35603 SUBJECT: Konus-Wind detection of GRB 240112A DATE: 24/01/23 11:56:59 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 long-duration GRB 240112A (GECAM-B detection: Wang and Xiong, GCN 35520; IPN triangulation: Kozyrev et al., GCN 35554) triggered Konus-Wind at T0=20481.732 s UT (05:41:21.732). The burst light curve shows the main multi-peaked episode, which starts at ~T0-0.2 s and has a total duration of ~2.8 s. A fainter broad pulse is observed in the KW data from ~T0+113 s to ~T0+120 s after the main pulse, whose association with GRB 240112A is supported by the consistent KW ecliptic latitude response. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB240112_T20481/ As observed by Konus-Wind, the burst (main episode) had a fluence of 7.58(-1.05,+1.13)x10^-6 erg/cm2, and a 64-ms peak flux, measured from T0+1.376 s, of 1.03(-0.19,+0.20)x10^-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The spectrum of the main episode (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 = -1.04(-0.21,+0.23), the high energy photon index beta = -2.67(-0.73,+0.26), the peak energy Ep = 120(-15,+20) keV (chi2 = 118/75 dof). The spectrum of the fainter broad pulse (measured from T0+106.752 to T0+123.136 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 = -1.67(-0.32,+0.53) and Ep = 206(-195,+1360) keV (chi2 = 71/86 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 = 71/85 dof). All the quoted errors are at the 90% confidence level. All the quoted values are preliminary. View this GCN Circular online at https://gcn.nasa.gov/circulars/35603. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...