{
  "body": "A. de Ugarte Postigo (INAF-OAB), A.J. Castro-Tirado, J. Gorosabel, M. \nJelínek, S. Guziy (IAA-CSIC), A. Cabrera-Lavers, D. García, G. Gómez \n(GTC/IAC), G. Bergond (CAHA), D. Pérez-Ramírez (Univ. de Jaén), R. \nCuniffe (IAA-CSIC) and P. Kubánek (IAA-CSIC, U. Valencia) report on \nbehalf of a larger collaboration:\n\n\"We have observed the field of the INTEGRAL GRB 091202  (Mereghetti et \nal. GCN 10234) using OSIRIS at the 10.4m Gran Telescopio Canarias (GTC) \nat the Observatorio del Roque de los Muchachos of the Instituto de \nAstrofísica de Canarias, in the island of La Palma. Observations were \ncarried out between 04:55 and 05:23 UT on 4 December 2009 (~1.25 days \nafter the burst). The observation consisted of 5x30s exposures in r, i \nand z bands. Addtional near-IR observations were obtained in with \nOmega2000 at the 3.5m telescope at the German-Spanish Calar Alto \nObservatory in J, H and K' bands between 01:06 and 04:46 UT.\n\nWithin the XRT error circle (Vetere et al. GCN 10239) we detect two \nsources, one point-like and one apparently extended in all three GTC \nframes. Only one source (point-like) shows up in the near-IR frame, \nwhich appears to be superimposed to the extended one seen in the \noptical. This will imply a strong red colour (r-H >= 4) typical of GRB \nafterglows (Gorosabel et al. 2002, A&A 384, 11). Hence, we identify this \nsource as the likely afterglow to GRB 091202, at coordinates (J2000.0):\n\nR.A.:  09 15 19.75\nDec.: +62 32 59.0\n\nwith a 0\".5 astrometry error.\n\nAt a mean epoch of 1.25 days after the burst, we measure for it a \nmagnitude of r = 23.7 ± 0.1. From the nIR observations we measure H = \n19.7 ± 0.2. at a mean epoch 1.21 days after the burst. For the optical \nphotometry we used the SDSS star located at coordinates R.A.: 09 15 \n21.23, Dec: +62 32 33.4 (J2000.0) for which we assume a magnitude of r = \n21.27. The nIR images were calibrated against a 2MASS star at \ncoordinates R.A.: 09 15 14.41, Dec: +62:31:55.5 (J2000.0) with H = 13.94.\n\nBased on the optical GTC image, at this moment we cannot rule out that \nthe optical flux arises from an underlying somehow extended blue galaxy \nwhereas the highly extincted afterglow is only observed in the nIR. A \nfigure showing the optical & nIR images of the likely afterglow to GRB \n091202 can be found at:  http://www.iaa.es/~gss/GRB091202\n\nThis message may be quoted.\"",
  "bibcode": "2009GCN.10247....1D",
  "createdOn": 1259972715000,
  "subject": "GRB 091202: GTC & CAHA optical/nIR afterglow candidate",
  "format": "text/plain",
  "submitter": "Alberto Castro-Tirado at Inst.de Astro. de Andalucia  <ajct@iaa.es>",
  "eventId": "GRB 091202",
  "email": "ajct@iaa.es",
  "version": 2,
  "circularId": 10247,
  "editedOn": 1731923183492,
  "editedBy": "Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Leo P. Singer at NASA/GSFC <leo.p.singer@nasa.gov>"
}