TITLE: GCN CIRCULAR NUMBER: 36830 SUBJECT: Konus-Wind detection of GRB 240627A DATE: 24/07/05 15:19:45 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 240627A (AstroSat-CZTI detection: Joshi et al., GCN 36776; NuSTAR anti-coincidence shields detection: Grefenstette, GCN 36778; CALET-CGBM detection: Kobayashi et al., GCN 36798; IPN triangulation: Kozyrev et al., GCN 36814;) triggered Konus-Wind at T0=86332.21 s UT (23:58:52.210). The burst light curve shows a multipeaked structure which starts at ~T0-45.2 s and has a total duration of ~91.0 s. The emission is seen up to ~4 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB240627_T86332/ As observed by Konus-Wind, the burst had a fluence of 5.22(-0.54,+0.57)x10^-5 erg/cm2, and a 64-ms peak flux, measured from T0+6.016 s, of 1.27(-0.23,+0.23)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+47.616 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 = -1.31(-0.07,+0.09), the high energy photon index beta = -2.47(-0.39,+0.20), the peak energy Ep = 191(-23,+25) keV (chi2 = 110/87 dof). The spectrum near the maximum count rate (measured from T0+5.376 to T0+7.168 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 = -1.06(-0.10,+0.11), the high energy photon index beta = -2.49(-0.63,+0.26), the peak energy Ep = 314(-54,+61) keV (chi2 = 49/55 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/36830. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...