TITLE: GCN CIRCULAR NUMBER: 31606 SUBJECT: GRB 220211A: redshift lower limit estimating DATE: 22/02/18 22:04:09 GMT FROM: Alexei Pozanenko at IKI, Moscow P. Minaev (IKI), A. Pozanenko (IKI) report on behalf of GRB IKI FuN: We analysed GRB 220211A (The Fermi GBM team, GCN 31570; Tohuvavohu et al., GCN 31582; Ridnaia et al., GCN 31584; Svinkin et al., GCN 31599) using publicly available data of GBM/Fermi. We estimate the duration in 7 - 850 keV energy band T_90 = 0.11 +/- 0.02 s. We performed spectral analysis in a time interval of (-0.05, 0.05) s, the best fit is obtained for CPL model with following parameters: E_p = 924 (-210, +317) keV, alpha = -0.50 +/- 0.25. The fluence of F = (5.8 +/- 0.5)E-7 erg/cm**2 is obtained in 10 - 1000 keV energy band. Using T_90,i - EH diagram [1,2] we classify the burst as type I (short) and find the minimal possible redshift value of z = 0.13 and the most probable value of the redshift z = 0.53. The T_90,i - EH diagram can be found in http://grb.rssi.ru/GRB220211A/GRB220211A_EHD.png The burst could also be classified as SGR Giant flare, placed at distance of D_L = 8.7 Mpc. [1] - Minaev et al., MNRAS, 492, 1919, 2020 [2] - Minaev et al., Astronomy Letters, 46, 9, 573, 2020