TITLE:   GCN CIRCULAR
NUMBER:  3493
SUBJECT: GRB 050525: RTT150, Optical observations
DATE:    05/05/27 15:44:50 GMT
FROM:    Irek Khamitov at TUG  <irekk@tug.tug.tubitak.gov.tr>

Z. Aslan, I. Khamitov, T. Ozisik, K. Uluc (TUG), U. Kiziloglu (METU),
I. Bikmaev, N. Sakhibullin (KSU/AST), A. Alpar (SabUni),
A.Yaskovich, R.Burenin, M. Pavlinsky, R. Sunyaev (IKI),
report:

     We have observed the field of OT of GRB 050525  (Rykoff et al, GCN3465)
with 2k*2k Andor CCD attached to the Russian-Turkish 1.5-m telescope
(Bakirlitepe, Turkey) in VRc bands.
     We made series of 5*90s exposures in V, starting at 00:22UT May 26,
and 20*60s exposures in Rc, starting at 01:18 UT May 26.
    On 20 co-added R-images we clearly see the OT at the position

RA = 18:32:32.57 (2000.0), DEC=+26:20:22.5 (2000.0)

based on the USNO-B1 catalog,  its uncertainty is about 0.1 arcsec.

We estimate m_R magnitude of OT using USNO-B1 as 21.76+/-0.17 
corresponding to the midtime of 25.5 hours after the burst.

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