{
  "bibcode": "2007GCN..6410....1M",
  "body": "D. Malesani, C.C. Thoene (DARK), A. Williams (Perth Obs.), J.P.U. Fynbo\n(DARK), A.O. Jaunsen (Univ. Oslo) and P.M. Vreeswijk (ESO) report on\nbehalf of a larger collaboration:\n\nWe observed the field of GRB 070509 (Vetere et al., GCN 6394) with the ESO\nVLT UT2 equipped with the FORS1 instrument. Short BVRI observations were\ncarried out between 2007 May 9.144 and 9.155 UT (starting 0.65 hr after\nthe GRB). We detect three objects close to the XRT position, at the\nfollowing coordinates (J2000, 0.5\" error):\n\nA:  RA = 15:51:49.29   Dec = -78:39:01.7   R = 23.48 +- 0.24\nB:  RA = 15:51:50.37   Dec = -78:39:06.4   R = 23.52 +- 0.25\nC:  RA = 15:51:50.91   Dec = -78:39:10.2   R = 22.71 +- 0.16\n\nObjects A and B are inside the XRT error circle as reported by Vetere et\nal. (GCN 6400), while objects B and C are inside the XRT error circle as\nprovided in Nat Butler's web page (revision 1.2,\nhttp://astro.berkeley.edu/~nat/swift/xrt_pos.html). Objects A and C are\nextended. Magnitudes are computed at the mean time 9.149 UT (0.78 hr after\nthe GRB) and are calibrated against the USNO-B1 catalog. The 3-sigma limit\nis R = 23.8. A finding chart of the field can be seen here:\n\nhttp://www.astro.ku.dk/~malesani/GRB/070509/finder_VLT.jpg\n\nFurther R-band observations were carried out with the 1.54m Danish\ntelescope located in La Silla (Chile) and equipped with DFOSC on 2007 May\n9.141 (4500 s) and May 13.134 UT (3000 s). Object C is marginally detected\nin both images, while objects A and B are below the detection limit.\n\nAt this stage, we cannot claim association between the GRB and any of the\nabove mentioned objects.\n\nWe acknowledge excellent support from the observing staff in Paranal, in\nparticular Alain Smette and Gael James. CT acknowledges Pisco and Bacardi\nsupport from the GROND staff at La Silla.",
  "circularId": 6410,
  "createdOn": 1179353304000,
  "email": "malesani@astro.ku.dk",
  "subject": "GRB 070509: objects inside XRT error circle",
  "submitter": "Daniele Malesani at Niels Bohr Inst,Dark Cosmology Center  <malesani@astro.ku.dk>",
  "eventId": "GRB 070509"
}