{
  "bibcode": "2009GCN.10000....0M",
  "body": "Daniele Malesani (DARK/NBI), Pall Jakobsson (Univ. Iceland), and Ilya \nIlyin (AIP), report on behalf of a larger collaboration:\n\nWe observed again the field of GRB 090904A (Perri et al., GCN 9879) with \nthe NOT equipped with StanCam. Observations were carried out in the R \nband, for a total exposure time of 30 min, with a mean time September \n6.218 UT (2.176 days after the GRB trigger).\n\nThe object identified in our previous epoch of imaging (Malesani et al., \nGCN 9884) has clearly faded and is hardly detectable, if at all. A faint \nsource is visible at its position, with magnitude R = 24.0 +- 0.3. If \nreal, the inferred decay slope is alpha = 0.55 +- 0.12, assuming F(t) \npropto t^-alpha. The value of alpha is shallower than usually found at \nlate times, and may indicate some host contribution or an unusual light \ncurve.\n\nThe position of the transient is consistent with the latest available \nUVOT-enhanced XRT position (Goad et al., GCN 9885; see also \nhttp://www.swift.ac.uk/xrt_positions/index.php). We thus identify the \nobject as the optical afterglow of GRB 090904A.\n\nA finding chart comparing the two epochs can be found at the following URL:\n\nhttp://www.astro.ku.dk/~malesani/GRB/090904A/GRB090904A_finder_NOT.jpg",
  "circularId": 10000,
  "createdOn": 1254978968000,
  "email": "malesani@astro.ku.dk",
  "subject": "GRB 090904A: afterglow confirmation",
  "submitter": "Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@astro.ku.dk>",
  "eventId": "GRB 090904A"
}