ИСТИНА

Event of a ground level enhancement (GLE) was detected by the worldwide network of neutron monitors. This is the second GLE event in the 24th solar cycle. It is produced in the active "Beta-Gamma-Delta" region А2673. During September 2017 the region produced a series of strong flares (up to X class). The flare which produced the GLE event was of X8.2 magnitude with coordinates S08W83 and started at 15:35 UT. GLE amplitude on neutron monitors did not exceed 6 % for 5-min data reduced to the sea level, and a lot of stations registered it. Fort Smith (Canada) was the first station detected the solar cosmic rays in 16:10 UT. At the nearest station Inuvik the increase began about half hour later. This is an evidence of a strong anisotropy on the first phase of GLE. We have analyzed the GLE event: energy spectra and pitch-angle distribution were derived using a methodic developed by PGI group. It includes calculation of asymptotic cone for each station using a modern magnetosphere model Tsyganenko-03 and solution of the inverse problem. This methodic was already used to calculate many GLE events of 19-23 cycles. Differential energy spectra during the event are derived with a 5-min step. The spectra are not purely power-law forms, but average slope is about γ = -4. This is hard (rigid) spectrum of solar cosmic rays. The results were compared with GOES spacecraft and balloon direct measurements on adjacent energy range. There is an acceptable agreement.