TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4711 SUBJECT: GRB 060121 : WIDGET Pre-trigger limit DATE: 06/02/08 01:11:42 GMT FROM: Toru Tamagawa at RIKEN K. Onda, K. Abe, M. Tashiro (Saitama-U), T. Tamagawa, Y. Urata (RIKEN), H. Azuma, M. Kuwahara (RIKEN/TUS), F. Usui (ISAS/JAXA) on behalf of the WIDGET collaboration report: "A very wide field camera, WIDGET, located at Akeno, Japan, observed the HETE-2 error region of GRB 060121 (Arimoto et al., GCN 4550). We continuously monitored the the region with repeat of unfiltered 5 sec exposure from 8 hours before the burst through the beginning of twilight (3.5 hours before the burst). Those images did not show any optical emission at the afterglow position reported by Malesani et al. (GCN 4561). The 1-sigma limiting magnitude of each frame derived by the Tycho 2 catalog is around V=10.7 magnitude." This message may be cited.