{
  "bibcode": "2015GCN.18609....1A",
  "body": "We observed the field of GRB 151027A (Maselli et al., GCN 18478) using\nthe 2m Himalayan Chandra Telescope of Indian Astronmical Observatory, \nHanle,\nIndia.  The GRB field was observed in Bessells R band, during 14:56 UT \nto\n16:20 UT on 2015-10-27. We obtained 20 frames, each  of 150 seconds\nexposure time.  The optical afterglow of  GRB 151027A (e.g., Maselli et \nal.,\nGCN 18478; Zheng & Filippenko, GCN  18479; Elenin et al., GCN 18480;\nPerley & Cenko, GCN 18481)  is clearly detected in each image. The\nmeasured magnitudes, calibrated using nearby  USNO B1.0 (R2 magnitudes)\nstars are listed below.\n\n---------------------------------------------------------------------\nTime (UT start)        Filter       Mag    error\n14:56                R          16.60   0.06\n15:36                R          16.67   0.07\n16:20                R          16.86   0.08\n-----------------------------------------------------------------------\n\nThis message may be cited.\n\nD.K. Sahu and G.C. Anupama (Indian Institute of Astrophysics, Bengaluru)",
  "circularId": 18609,
  "createdOn": 1447676189000,
  "email": "gca@iiap.res.in",
  "subject": "GRB151027A; Optical observations",
  "submitter": "G.C. Anupama at IIA,Bangalore  <gca@iiap.res.in>",
  "eventId": "GRB 151027A"
}