{
  "bibcode": "2021GCN.31228....1D",
  "body": "A. de Ugarte Postigo (Obs. Cote d���Azur), D.A. Kann, C. Thoene, \nJ.F. Agui Fernandez, M. Blazek (HETH/IAA-CSIC), I. Vico and \nA. Guijarro (CAHA) report: \n\nWe obtained a second imaging observation of the optical afterglow \nof GRB 211211A (Fermi team GCN31201; D���Ai et al. GCN31202; \nZheng and Filipenko GCN 31203) with CAFOS, mounted on the \n2.2m telescope, at the Calar Alto Observatory (Almer��a, Spain). \n\nThe observation started at 04:47 UT (39.6 hr after the GRB) and \nconsisted of 30x90s in i-band. The optical afterglow is still detected, \nat a magnitude (AB) of i = 22.45+/-0.09, as compared to field stars \nfrom the SDSS catalogue. With respect to our earlier CAFOS \nphotometry (de Ugarte Postigo et al. GCN 31218) this implies a \nrapid decay rate of alpha = 1.65, where F_nu ~ t^-alpha, which \nwould indicate a post-jet break evolution.",
  "circularId": 31228,
  "createdOn": 1639416164000,
  "email": "deugarte@iaa.es",
  "subject": "GRB 211211A: Further observations from CAFOS/2.2m CAHA",
  "submitter": "Antonio de Ugarte Postigo at IAA-CSIC  <deugarte@iaa.es>",
  "eventId": "GRB 211211A"
}