TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  2826
SUBJECT: GRB041006: RTT150 Optical Observations 
DATE:    04/10/19 17:43:19 GMT
FROM:    Irek Khamitov at TUG  <irekk@tug.tug.tubitak.gov.tr>

I. Bikmaev, N. Sakhibullin (Kazan State University),
M.A. Alpar (Sabanci U.), U. Kiziloglu, S. Balman (METU),
Z. Aslan, I. Khamitov (TUG),
R. Burenin, M. Pavlinsky, R. Sunyaev (IKI),

   We observed the afterglow of GRB 041006 (G. Da Costa et al., GCN 2765,
P.A. Price, GCN 2766), discovered by HETE (M. Galassi et al., GCN 2770), 
with Russian-Turkish 1.5-m telescope (Bakyrlytepe, TUBITAK National 
Observatory, Turkey).
   We made 48 x 300 sec images in R  between  Oct. 18, 19:50 UT, and Oct.
19, 00:37 UT (12.4 d after the burst) using the imaging ANDOR CCD. The
seeing was 1.3-1.6" and weather was clear.
   We detected the source at combined image with m_R = 24.0+/-0.2. For 
calibration of the R band images we used the reference stars reported in 
(A. Henden, GCN 2801).
   Part of 8 x 8 arcmin combined RTT150 image of the field and the source
location is presented at:

   http://www.tug.tubitak.gov.tr/~irekk/grb/grb041006/GRB041006_Oct18.jpg

   Our measurement of R magnitude shows clear deviation on the
extrapolation of  the early detections  on R band light curve and
confirms our previous OT detection above the extrapolation
(S.Balman et al., GCN 2821).
   We, probably, see the supernova re-brightening, or the host galaxy.
Supernova bump is more probable since the OT is outside the center of
the host galaxy (J.Fynbo et al., GCN 2802, S. Covino et al., GCN 2803)
and its brightness is still higher than that of the host.

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