{
  "bibcode": "2009GCN..9687....1M",
  "body": "D. Malesani (DARK/NBI), G. C. Cox (NOT), C. Mackay, D. King, T. Staley \n(IoA Cambridge), and P. Jakobsson (Univ. Iceland) report on behalf of a \nlarger collaboration:\n\nWe observed again the field of GRB 090715B (Vetere et al., GCN 9668) \nusing the NOT telescope equipped with the StanCam instrument. The \noptical afterglow (Vetere et al., GCN 9668; Smith et al., GCN 9670) is \nwell detected in the V and R filters, and is still bright. Using the \nsame reference star as in GCN 9671, we measure R ~ 21.3 on mean time \nJuly 17.94 UT (2.06 days after the GRB).\n\nAssuming an unbroken power-law fading (Fnu propto t^-alpha), the \ncorresponding decay index is alpha ~ 0.44, which is unusually flat at \nsuch late epoch (although not unprecedented). Our measurement is also \nconsistent within the uncertainties with the broken power-law fit \nreported by Guidorzi et al. (GCN 9677).\n\nDM thanks Carole G. Mundell and Cristiano Guidorzi for discussion.",
  "circularId": 9687,
  "createdOn": 1247931106000,
  "email": "malesani@astro.ku.dk",
  "subject": "GRB 090715B: further NOT optical observations",
  "submitter": "Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@astro.ku.dk>",
  "eventId": "GRB 090715B"
}