{
  "bibcode": "2015GCN.17500....1D",
  "body": "Antonio de Ugarte Postigo (IAA-CSIC, DARK/NBI), Christina Thoene (IAA-CSIC), \nand Victor Casanova (IAA-CSIC) report on behalf of a larger collaboration:\n\nWe observed the field of GRB 150222A (Bernardini et al., GCN 17486) with the \n1.5 m telescope at Sierra Nevada Observatory (Granada, Spain). \nObservations consisted of 34x300s in I-band and ranged from 2:46 to 5:44 UT \n(mid epoch at 4:15 UT, or 11.31 hr after the burst trigger). Observing conditions \nwere poor, with a seeing of 2.9\". We do not detect the optical counterpart \ncandidate reported by Mazaeva et al. (GCN 17489) and Nicuesa Guelbenzu et al.\n(GCN 17495) or any other object within the enhanced XRT error circle (Beardmore\net al. GCN 17494). The 3-sigma limit of the combined image is I(Vega) = 22.5 mag,\nas compared with USNOB-1.0 stars.\n \nConsidering an optical decay slope of alpha ~ 1.1 (where F_nu ~ t^(-alpha)) \nbetween the epochs of Mazaeva et al. and Nicuesa Guelbenzu et al., and a typical \nGRB colour, our observation is consistent with the expected brightness and is also \nconsistent with the non-detections reported by other groups (Ivanov et al. GCN \n17487; Klotz et al. GCN 17488; Malesani et al. GCN 17493; Kuin et al. GCN 17499)",
  "circularId": 17500,
  "createdOn": 1424698919000,
  "email": "deugarte@iaa.es",
  "subject": "GRB 150222A: I-band observations from OSN",
  "submitter": "Antonio de Ugarte Postigo at IAA-CSIC  <deugarte@iaa.es>",
  "eventId": "GRB 150222A"
}