[vsnet-grb-info 4847] GRB 070616 : WIDGET simultaneous optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  6579
SUBJECT: GRB 070616 : WIDGET simultaneous optical observations
DATE:    07/06/26 08:03:05 GMT
FROM:    Makoto Tashiro at Saitama U/Swift  <tashiro at phy.saitama-u.ac.jp>

N. Kodaka,  K. Onda, Y. Urata, W. Iwakiri, T. Sugasahara, M. Tashiro
(Saitama-U),  M. Kuwahara (TUS/RIKEN), T. Tamagawa (RIKEN) F. Usui
(ISAS/JAXA) report:

"We observed the error region of GRB 070616 (Swift/BAT trigger #282445;
Starling et al., GCN 6542; Sakamoto et al., GCN circ 6543; Starling et
al., GCN Report 66.2) with the very wide-field camera WIDGET located at
Kiso, Japan. The WIDGET monitored the region with repeat of unfiltered
5-second exposures between 27 seconds before and 136 seconds after the
burst.

We did not find any  optical emission from the afterglow position
(Fatkhullin et al. GCN  6547). The 1-sigma limiting magnitude of
each frame derived by the Tycho-2 catalog was around V=11.8 magnitudes."

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