{
  "bibcode": "2001GCN...985....1M",
  "body": "N. Masetti, E. Palazzi (ITeSRE, CNR, Bologna), E. Pian (Oss. Astron. Trieste),\nA. Zacchei, A. Magazzu, M. Pedani, F. Ghinassi (TNG) and M. Mignoli\n(Oss. Astron. Bologna), on behalf of a larger collaboration, report:\n\n\n\"We observed the optical transient (Henden, GCNs #961, #962) associated\nwith GRB010222 (Piro, GCNs #959, #960) in the R band with TNG+Dolores\non 2001 Feb. 24.236 UT (i.e. ~2 days after the GRB). The total exposure\ntime was 4 minutes; seeing was 0.9 arcsec.\n\nUsing star `A' by Stanek et al. (GCN #970) as reference, we note that our\nmeasurement, R = 20.88 +- 0.03, is ~0.4 mag fainter than the extrapolation\nof the t^{-0.9} decay measured by Price et al. (GCN #973), Fynbo et al.\n(GCN #975) and Stanek et al. (GCN #983). \n\nThe power-law decay between our TNG measurement and that made in the R\nfilter by Stanek et al. (GCN #983) on Feb. 23.45 has an index ~1.3. Thus,\nour data seem to suggest that a break occurred at ~1 day after the GRB in \nthe R-band light curve of the afterglow.\n\nFurther observations are strongly encouraged to confirm (or reject) this\nresult.\".\n\nThis message can be cited.",
  "circularId": 985,
  "createdOn": 983041149000,
  "email": "masetti@tesre.bo.cnr.it",
  "subject": "GRB010222, possible increase of optical decay slope",
  "submitter": "Nicola Masetti at ITeSRE,CNR,Bologna  <masetti@tesre.bo.cnr.it>",
  "eventId": "GRB 010222"
}