[vsnet-grb-info 2874] GRB 060121 : WIDGET Pre-trigger limit

[GCN Circulars]

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  <tamagawa at riken.jp>

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." 

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