[vsnet-grb-info 14012] Fermi403206457: Weihai optical upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15326
SUBJECT: Fermi403206457: Weihai optical upper limit
DATE:    13/10/13 05:42:47 GMT
FROM:    Dong Xu at DARK/NBI  <dong.dark at gmail.com>

D. Xu (DARK/NBI), C.-M. Zhang, C. Cao, S.-M. Hu (SDU) report:

We observed the location of the candidate optical afterglow
(iPTF13dsw; Kasliwal et al., GCN 15324) of the Fermi-GBM trigger
403206457 with the 1m telescope located in Weihai, Shandong, China. We
obtained 5x600s R-band frames at a mean time of 2013-10-12 18:01:29 UT
(i.e., 24.23 hr after the Fermi-GBM trigger) under some clouds.

No optical source is detected at the iPTF location in the stacked
image down to a limiting magnitude of R > ~20.0 mag, calibrated with
the nearby SDSS field.