{
  "bibcode": "2021GCN.29474....1D",
  "body": "P. D'Avanzo, S. Covino, D. Fugazza, A. Melandri (INAF-OAB) on behalf of the REM team, report:\n\nWe observed the field of GRB 210211A (Troja et al., GCN Circ. 29472) with the REM 60cm robotic \ntelescope located at the ESO premise of La Silla (Chile). The observations were performed starting \non 2021 February 11 at 08:44:54 UT (i.e. 96 seconds after the burst) and were carried in the g, r, i, z, H \nbands simultaneously. \n\nFrom a preliminary analysis of the first set of images, obtained at a mid time of t-t0 = 101 s we detect in \nall filters an uncatalogued object at the following position: \n\nRA (J2000), Dec (J2000) = 17:57:45.67, -46:16:01.8 (+/- 0.5\")\n\nwith a magnitude r = 16.9 +/- 0.1 (AB; calibrated against the APASS catalogue). This source is found about \n1.5 magnitudes fainter in a subsequent set of images obtained at t-t0 = 204 s. \n\nThe source position lies about 8\" outside the current available XRT error circle (https://www.swift.ac.uk/xrt_positions/). \nHowever, the observed brightness and rapid fading suggests that it is the optical/NIR afterglow of GRB 210211A. \nWe also note the presence of an optical/NIR source inside the XRT error circle whose magnitude does not show significant \nvariation in our dataset. \n \nFurther analysis is in progress.",
  "circularId": 29474,
  "createdOn": 1613042374000,
  "email": "pda.davanzo@gmail.com",
  "subject": "GRB 210211A: REM optical/NIR afterglow detection",
  "submitter": "Paolo D'Avanzo at INAF-OAB  <pda.davanzo@gmail.com>",
  "eventId": "GRB 210211A"
}