[vsnet-grb-info 2657] GRB060111A: RTT150 optical observations

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4494
SUBJECT: GRB060111A: RTT150 optical observations
DATE:    06/01/12 08:57:42 GMT
FROM:    Irek Khamitov at TUG  <irekk at tug.tug.tubitak.gov.tr>

I. Khamitov, K. Uluc, Z. Aslan (TUG), U. Kiziloglu (METU),
E. Gogus (Sabanci Uni.), T. Saygac, O. Onal (Ist. Uni.)
R. Burenin, M. Pavlinsky, R. Sunyaev (IKI)
I. Bikmaev, N. Sakhibullin (KSU/AST)

report:

We observed field around of possible optical counterpart (Blustin et
al., GCN4482) of GRB060111A (Swift trigger 176818) with Russian-Turkish
1.5-m telescope (RTT150, Bakyrlytepe, TUBITAK National Observatory,
Turkey), starting on Jan. 12, 03:37UT, i.e. ~23.2 hours after the burst.

A series of frames (8*300s exposures in R band) were taken. The
afterglow candidate was detected only marginally near the detection
limit of our combined image, which is estimated as R~23.2 (photometry is
USNO-B1 calibrated). We also note that at about 5 arcsec from the OT we
detected an extended source whith R=21.75+/-0.1, which may be a host
galaxy of the GRB. The coordinates of this galaxy are RA= 18h24m49.01s
(J2000.0) DEC=+37d36'09."6 (J2000.0).

The finding chart can be found at:
http://www.tug.tubitak.gov.tr/~irekk/grb/grb060111a/grb060111A.JPG

Also we have to do a correction to GCN4493: We detected extended source
in direction to SE, not NW. The upper limit for the GRB060111B OT is
also actually deeper: R=~23.6 (the difference is due to corrected error
in photometric calibration).

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