{
  "bibcode": "2021GCN.31053....1P",
  "body": "A. Pozanenko (IKI), A. Moiseev (SAO RAS), A. Moskvitin (SAO RAS), E. \nMalygin (SAO RAS), S. Belkin (IKI, HSE), N. Pankov (IKI, HSE), V. Kim \n(HSE, FAI) on behalf of GRB IKI FuN, A. Rossi (INAF-OAS), D. A. Kann \n(HETH/IAA-CSIC) report:\n\nWe observed the afterglow of GRB 211023A (Zhirkov et al, GCN 30977, see \nalso  Kann et al, GCN 30982; Hu et al,  GCN 30990; Belkin et al, GCN \n31004; Vinko et al, GCN 31008; Belkin et al, GCN 31018; Belkin et al, \nGCN 31020; Kumar et al, GCN 31023; Gupta et al., GCN 31041; Strobl et \nal., GCN 31042)  with BTA  SAO RAS telescope equipped with SCORPIO-2 \n(VPHG940@600 grism). A total of 7200 s (6x1200 s) of spectra were \nobtained starting on 21-11-05 (UT) 20:50:00, i.e. approximately 13.3016 \ndays after burst. The afterglow is well detected in the acquisition \nimaging with R = 21.61 +/- 0.04 (3 x 90 sec. 21-11-05 (UT) 20:43:59 -- \n20:50:58), and a continuum is visible across the bandwidth of a spectrum \n4000 - 8500 A. The spectrum contain  significant emission lines H_beta, \n[OII] 3727, [OIII] 5007,  at a common redshift of z=0.390. We assume \nthat the lines are from a host galaxy and, therefore, this is the \nredshift of GRB 211023A. No evident lines of a possible SN were found.\n\nCalibration of photometry is preliminary and based on nearby stars of \nPS1 catalogue, gri -> R by Lupton transformations.\n\nWe are grateful to the directorate of SAO RAS for the TOO allocation.",
  "circularId": 31053,
  "createdOn": 1636384593000,
  "email": "apozanen@iki.rssi.ru",
  "subject": "GRB 211023A: BTA spectroscopic redshift",
  "submitter": "Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>",
  "eventId": "GRB 211023A"
}