TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1887 SUBJECT: GRB 030226 simultaneous optical observations DATE: 03/02/26 20:10:17 GMT FROM: Alberto Castro-Tirado at LAEFF-INTA A. J. Castro-Tirado (IAA-CSIC and LAEFF-INTA), A. de Ugarte Postigo (IAA-CSIC), T. J. Mateo Sanguino, M. T. Fernández Palomo (CEDEA-INTA), M. Jélinek, P. Kubánek, R. Hudec (ASU), S. Vitek, P. Páta (CVUT) and J. Á. Berná (Univ. de Alicante) on behalf of the BOOTES team, report: "We have obtained several unfiltred exposures (180-s each) under thin thirrus covering the GRB 030226 error box. The images covered the period 03:45:16 - 03:56:26 UT 26 Feb 2003 (i.e. between 1.5-minutes before the trigger and 9.9-minutes after the trigger) with the wide-field camera of BOOTES-1. After a visual inspection of the HETE-2 error box in all frames, we do not find evidence of optical emission at the position of the bright optical counterpart (GCNC 1879, 1881, 1882), in particular simultaneously to the burst itself, for which we have an image covering the time interval 03:45:16 - 03:48:16 UT. Therefore we derive an upper limit of R = 11.5 for the reverse shock emission (if any) arising from this GRB, in contrast to the 9-th magnitude prompt flash emission recorded for GRB 990123 (Akerloff et al. 1999, Nat 398, 400)". This message can be cited.