[vsnet-grb-info 4512] GRB 070412: Optical observations at Crni Vrh

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  6284
SUBJECT: GRB 070412: Optical observations at Crni Vrh
DATE:    07/04/12 09:40:32 GMT
FROM:    Herman Mikuz at OCV  <herman.mikuz at fmf.uni-lj.si>

H. Mikuz, J. Skvarc and B. Dintinjana on behalf of PIKA observing program at
Crni Vrh Observatory:

We observed a 42'x42' field centered on Swift position at ra=12:06:01
dec=+40:06:03 (J2000), using 60 cm Cichocki robotic telescope at Crni Vrh
Observatory,  Slovenia.  There is no obvious source down to R magnitude
20.7 +/-0.1 inside the error box 3x3 arc minutes on 90 s R filter
exposure, starting at 2007 Apr. 12 01:39:03 UT (46 seconds after reception
of the alert) and 5 subsequent images of the same duration. Magnitudes
were calibrated against the USNO-B1 catalogue. In particular we also do
not observe any source to this limiting magnitude at the coordinates
reported by NOT (Malesani and Uthars, GCN 6276) or Jelinek et al. (GCN
6279).