{
  "bibcode": "2004GCN..2535....1T",
  "body": "G. Tagliaferri, D. Fugazza, S. Covino, N. Cucchiara, P. D'Avanzo,\nS. Kalogerakos, A. Simoncelli, F.M. Zerbi (INAF-OAB);\nG. Chincarini  (UNIMIB & INAF-OAB); O. Hainaut (ESO-La Silla);\nG.L. Israel, L. Stella (INAF-OAR); D. Malesani (SISSA);\non behalf of a larger collaboration report:\n\nWe observed the field of the INTEGRAL GRB 040223 (Gotz et al. GCN 2525)\nwith SofI at the ESO-NTT telescope in the JHKs filters. We observed this\nfield three times, at Feb 24.258, Feb 24.383 and Feb 25.361 UT (i.e. 0.70,\n0.82, and 1.8 days after the GRB). In the Ks-band the seeing was of 1.0,\n0.6 and 0.7 arcsec, respectively.\n\nWe detect 32 sources with Ks magnitude between 15.0 and 19.9  within a\nsquare box of 12.5 arcsec, which corresponds to the XMM-Newton error\ncircle  (Breitfellner et al. GCN 2530). The brightest five have the \nfollowing\nmagnitudes (calibrated to the 2MASS):\n\n Ra(2000)   Dec(2000)    K1s              K2s             K3s\n-----------------------------------------------------------------------\n16:39:30.2 -41:56:03.3  14.91 +/- 0.11   14.93 +/- 0.08  15.00 +/- 0.10\n16:39:29.3 -41:56:01.2  15.48 +/- 0.11   15.44 +/- 0.08  15.52 +/- 0.10\n16:39:29.5 -41:55:59.8  15.55 +/- 0.12   15.58 +/- 0.09  15.61 +/- 0.10\n16:39:29.6 -41:56:08.8  16.28 +/- 0.12   16.15 +/- 0.08  16.25 +/- 0.10\n16:39:29.5 -41:56:06.2  16.70 +/- 0.12   16.62 +/- 0.09  16.76 +/- 0.10\n\nWe do not observe significant variability for the sources detected in the\nXMM-Newton error box between the three exposures. Therefore, we have no\nindication of a transient associated with the XMM-Newton source. A full\nanalysis of these data is in progress. More observations at ESO are not\nplanned.\n\nFor the NTT SofI Ks finding charts and the list of sources detected in \nthe XMM-Newton\nerror box, see http://www.merate.mi.astro.it/~taglia/GRB040223/grb.html\n\nWe thank the ESO La Silla staff for their prompt reaction and support.\nThis message can be cited.",
  "circularId": 2535,
  "createdOn": 1077830498000,
  "email": "taglia@merate.mi.astro.it",
  "subject": "GRB 040223: Deep NIR NTT observations",
  "submitter": "Gianpiero Tagliaferri at OAB-INAF  <taglia@merate.mi.astro.it>",
  "eventId": "GRB 040223"
}