[vsnet-grb-info 1943] GRB050803: CrAO optical observations, no OT candidate

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3783
SUBJECT: GRB050803: CrAO optical observations, no OT candidate
DATE:    05/08/10 17:58:30 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

E. Pavlenko, A. Shlyapnikov, Yu. Efimov, A. Baklanov, V. Rumyantsev  (CrAO),
A.Pozanenko (IKI), D. Sharapov, M. Ibrahimov, (MAO) on behalf of larger GRB
follow up collaboration report:

We observed XRT error box (Racusin et al., GCN 3752)  of   GRB050803 (Band
et al., GCN 3748) with 2.6m Shain telescope (CrAO) on August 3 (Pavlenko et
al., GCN 3760) and August 4.  The object mentioned in GCN 3753 (Berger et
al.) is detected in both epochs.  We recalibrated our data (Pavlenko et al.,
GCN 3760) and found the R-magnitude  of the object:

 Mid time Aug.3, (UT)22:02 R = 22.10 +/- 0.10
 Mid time Aug.4, (UT)21:41 R = 22.05 +/- 0.05

which is in agreement with photometry reported in GCN 3763 (Burenin et al.).
Since no variability of the proposed object is detected it cannot be
considered as OT candidate.

Meanwhile extended object is detected in the FOV with coordinates RA(J2000)=
23:22:38.73 Dec(J2000)=05:47:12.4 at Aug.3, (UT) 22:02 with R=21.78 +- 0.03
which is not visible on Aug. 4 observations. Detailed analysis shows that it
is an asteroid with velocity ~0.005 arcsec/sec toward N-W. The detected
asteroid in not presented in the catalogs of Minor Planet Center
(http://cfa-www.harvard.edu/cfa/ps/mpc.html).

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