{
  "bibcode": "2009GCN..9531....1C",
  "body": "Z. Cano (Liverpool JMU), C. Guidorzi (U. Ferrara), D. Bersier,\nA. Melandri, I.A. Steele, R.J. Smith, C. Mundell (Liverpool JMU)\nreport, on behalf of a large collaboration:\n\nFollowing our report of observations (GCN 9520) we continued monitoring\nthe field of GRB090618 (Swift trigger 355083) on the Liverpool Telescope\n(La Palma) from 13.6 hours to 17.9 hours post burst in R and i bands.\nBelow is a summary of a few R-band images:\n\nt_exp  t-T0          R-mag\n\n300s   13.6 hours    18.9 � 0.1\n300s   15.6 hours    19.1 � 0.1\n300s   17.9 hours    19.3 � 0.1\n\nThe calibration is still preliminary and determined against stars in\nthe USNO catalog.\n\nWe note a break in the R-band light curve, and find a decay index of\nalpha~1.4 by 17.9 hours post burst, as compared to alpha~0.7 previously\nreported (GCNs 9517, 9520).",
  "circularId": 9531,
  "createdOn": 1245401779000,
  "email": "zec@astro.livjm.ac.uk",
  "subject": "GRB090618 - Continued optical monitoring and light curve  break",
  "submitter": "Zach Cano at ARI/John Moores Liverpool  <zec@astro.livjm.ac.uk>",
  "eventId": "GRB 090618"
}