{
  "bibcode": "2009GCN..9488....1X",
  "body": "D. Xu, G. Leloudas, D. Malesani, J. P. U. Fynbo, J. Hjorth (DARK/NBI), \nP.  Jakobsson (Univ. Iceland), and T. Liimets (NOT & Tartu Obs.) report \non behalf of a larger collaboration:\n\nWe continued to observe the field of GRB 090530 (Cannizzo et al., GCN \n9438) with the Nordic Optical Telescope equipped with ALFOSC.  We \nobtained 3x600 s R-band frames staring on June 01, 22:04:19 UT, 66.7669 \nhr after the burst.\n\nThe optical afterglow (Cannizzo et al., GCN 9438) is still detected in \nthe stacked frame. The magnitude is R=22.6+/-0.2 against the same \nreference star in Malesani et al. (GCN 9452).\n\nBalman et al. (GCN 9487) found a 3sigma upper limit of R=21.1+/-0.5 mag \nat 15.2 hr after the burst. Our first observation shows R=21.6 mag at \n17.8 hr after the burst. Rossi et al. (GCN 9458) found R=22.2+/-0.2 mag \nat 21.3 hr after the burst, and a break in the light curve at around 22 \nksec post-burst with slopes of 0.5+-0.1 (pre-break) and 1.8+-0.4 \n(post-break), using previous obs (Flewelling et al., GCN 9439; Schady et \nal., GCN 9450; Nissinen & Hentunen, GCN 9442). Our new observation \nindicates that the optical decay is becoming much slower. The slower \noptical decay may be due to the presence of a fairly bright host galaxy.\n\nFurther optical observations are encouraged.",
  "circularId": 9488,
  "createdOn": 1244058699000,
  "email": "dong@astro.ku.dk",
  "subject": "GRB 090530: Further NOT optical observations",
  "submitter": "Dong Xu at DARK,NBI  <dong@astro.ku.dk>",
  "eventId": "GRB 090530"
}