[vsnet-grb-info 2499] GRB 051211b: RTT150 optical observations

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4336
SUBJECT: GRB 051211b: RTT150 optical observations
DATE:    05/12/12 11:55:05 GMT
FROM:    Rodion Burenin at IKI, Moscow  <rodion at hea.iki.rssi.ru>

I. Khamitov (TUG), I. Bikmaev, R. Zhuchkov, N. Sakhibullin (KSU/AST)
Z. Aslan (TUG), U. Kiziloglu (METU), E. Gogus (Sabanci Uni.),
R. Burenin, M. Pavlinsky, R. Sunyaev (IKI)

report:

The error box of GRB 051211b (INTEGRAL trig. 2712; Mereghetti et al,
GCN4327) was observed with Russian-Turkish 1.5-m telescope (RTT150,
Bakyrlytepe, TUBITAK National Observatory, Turkey), starting at Dec. 11,
22:23UT, i.e. 18 min after the burst. Observations were started at
zenith distance Z=69 degrees and were continued until the object
descended into the clouds near the horizon.

We made 30x60s exposures in R. The first 20 images were taken in clear
sky but the last 10 images show a variable background because of clouds
and bright Moon. We did not find the afterglow candidate reported by
Klotz et al. (GCN4328) nor on first 60s image nor on image of 20
co-added good images.

At the XRT position (Pagani et al., GCN 4332) we marginally detected
only one source near the detection limit of our combined image. The
coordinates of this source are: 23:02:42.25 +55:04:53.4 (J2000). The
finding chart can be found at:

http://hea.iki.rssi.ru/~rodion/GRB/051211b/r.jpg

Using USNO-B1 stars we estimate limiting magnitude in our combined image
as R=~22.3.

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