{
  "bibcode": "2003GCN..2476....1T",
  "body": "GRB 031203: Deep NIR NTT & VLT observations\n\n\nG. Tagliaferri, S. Covino, D. Fugazza, S. Campana, A. Simoncelli (INAF-OAB)\nG. Chincarini (UNIMIB & INAF-OAB), L. Stella (INAF-OAR)\n\n\nOn December 5th, at 06:12 UT, we started observing in JHKs filters with \nISAAC\nat the VLT-UT1 telescope the XMM source S1 (Santos-Lleo & Calderon \nGCN2464).\nIn the XMM error box of 6\" around S1 we detect the source already seen \nin the\nprevious night with the NTT (Zerbi et al. GCN2471, see also Hsia et al. \nGCN2470).\n\nWith ISAAC we obtained the following magnitudes (based on 2MASS stars):\nJ=18.40+/-0.15, H=17.80+/-0.15 and Ks=16.70+/-0.15. A comparison between the\nNTT values on December 4 and the VLT one of the following night shows that\nthis object faded by few tens of magnitude. Given that this object was \nalready\ndetected in archive images (Bloom et al. GCN2472), it is probably a \nvariable star.\n\nIn the XMM error box with ISAAC we detect also another source with \nJ=21.05+/-0.25\n(not visible in H and Ks). This object was already present in the SofI J \nimage and\nit does not seem to have varied. We did not see any variable source in \nan area of\n20 arcsecond radius around the XMM S1 position. Therefore, we have no \nindication of\na transient associated with GRB 031203. However, note that the VLT \nimages do not cover\nthe full INTEGRAL error box, in particular the area around the XMM S2 \nsource is not in the FoV.\n\n\nFor the NTT SofI Ks finding charts, see \nhttp://www.merate.mi.astro.it/~taglia/GRB031203.jpg\n\nWe thank the ESO La Silla and Paranal staff for their prompt reaction \nand support.\nThis message can be cited.",
  "circularId": 2476,
  "createdOn": 1070720187000,
  "email": "taglia@merate.mi.astro.it",
  "subject": "GRB 031203: Deep NIR NTT & VLT observations",
  "submitter": "Gianpiero Tagliaferri at OAB-INAF  <taglia@merate.mi.astro.it>",
  "eventId": "GRB 031203"
}