TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3140
SUBJECT: GRB050319: optical observation, March 20-22
DATE:    05/03/24 14:36:37 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

D. Sharapov, M. Ibrahimov,  R. Karimov, B. Kahharov (UBAI), A.Pozanenko
(IKI), V.Rumyantsev (CrAO),  G.Beskin (SAO) report:

We continue observation (Sharapov et al. GCN 3124) of GRB050319 afterglow
(Rykoff et al.  GCN 3116, Krimm et al. GCN 3117) with 1.5m telescope of
Maidanak Astronomical Observatory, Mt.Maidanak, Uzbekistan. R-band images
were taken in several sets of observation on March 19-22. Preliminary
photometry against of USNO-B1.0 Catalog is following:

Mean time  Exposure Filter  Mag.
(UT)         (s)

Mar.20 21:49  2640   R   21.62 (0.07)
Mar.21 21:34  1560   R   21.67 (0.09)
Mar.22 18:41  1260   R   21.27 (0.13)

Observations obtained on March 22 are not compatible with power law index
decay  1.59 (.05) for early and first day afterglow observations (Torii et
al. GCN 3132, Quimby, GCN 3135) suggesting a presence of knee or
re-brightening of the afterglow light curve.

Excellent seeing conditions during the observations on Mar. 22 (~0.7") allow
us to investigate some details of the field objects. In particular IDs
(USNO-B1.0) 1335-0213759 and 1335-0213777 seem to be galaxies, and ID
1335-0213724 is a variable star. All above is leaving a few field stars for
calibration.

Deep field photometry for correct calibration would be encouraged.

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