{
  "subject": "Konus-Wind detection of GRB 250202B",
  "createdOn": 1738762811692,
  "submitter": "Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>",
  "bibcode": "2025GCN.39149....1F",
  "body": "D. Frederiks, A.Lysenko, A. Ridnaia, D. Svinkin,\nA. Tsvetkova,  M. Ulanov, and T. Cline,\non behalf of the Konus-Wind team, report:\n\nThe long GRB 250202B (Fermi-GBM detection: The Fermi GBM team, GCN 39120;\nBala et al., GCN 39133; AstroSat-CZTI detection: Srijan et al., GCN 39122;\nNuSTAR-ACS detection: Grefenstette, GCN 39135; IPN triangulation: Svinkin et al., GCN 39144)\ntriggered Konus-Wind (KW) at T0=14235.288 s UT (03:57:15.288).\n\nThe burst light curve consists of multiple multi-peaked emission pulses.\nThe total duration of the burst is ~100 s.\nThe emission is seen up to ~10 MeV.\n\nThe Konus-Wind light curve of this GRB is available at\nhttp://www.ioffe.ru/LEA/GRBs/GRB250202_T14235/\n\nAs observed by Konus-Wind, the burst had\na fluence of (2.05 ± 0.07)x10^-4 erg/cm^2 and\na 64-ms peak energy flux, measured from T0 + 2.112 s,\nof (1.62 ± 0.10)x10^-5 erg/cm^2/s (both in the 20 keV - 10 MeV energy range).\n\nThe time-integrated spectrum (measured from T0 to T0+106.240 s)\nis best fit in the 20 keV - 15 MeV range\nby a GRB (Band) function with the following model parameters:\nthe low-energy photon index alpha = -0.87 (-0.05,+0.06),\nthe high energy photon index beta = -2.67 (-0.12,+0.09),\nthe peak energy Ep = 273 (-8,+9) keV,\nchi2 = 121/97 dof.\n\nThe spectrum near the peak count rate (measured from T0 to T0+2.560 s)\nis best fit in the 20 keV - 15 MeV range\nby a GRB (Band) function with the following model parameters:\nthe low-energy photon index alpha = -0.38 (-0.07,+0.08),\nthe high energy photon index beta = -3.40 (-0.72,+0.33),\nthe peak energy Ep = 413 (-21,+21) keV,\nchi2 = 63/60 dof.\n\nAll the quoted errors are estimated at the 68% confidence level.\nAll the presented results are preliminary.\n",
  "eventId": "GRB 250202B",
  "circularId": 39149,
  "submittedHow": "email"
}