TY JOUR TI Auroras during extreme geomagnetic storms: Visual observations of the SAR arc in Irkutsk during the 1859 Carrington event KW carrington event KW auroras KW SAR arc KW mid-latitude airglow JO Solnechno-Zemnaya Fizika AU Mikhalev, A.V. AU Beletsky, A.B. PY 2025 IS 11 PB Institute of Solar-Terrestrial Physics SB RAS