[vsnet-grb-info 1902] GRB 050730: OHP optical observations

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3741
SUBJECT: GRB 050730: OHP optical observations 
DATE:    05/08/03 08:42:35 GMT
FROM:    Jean-Luc Atteia at Lab d Astrophys.,OMP,Toulouse  <atteia at ast.obs-mip.fr>

Damerdji, Y. (OHP), Klotz, A. (CESR-OMP),
Boer M. (OHP), Atteia J.L. (LATT-OMP) report:

We imaged the field of GRB 050730
detected by SWIFT (Holland et al. GCNC 3704)
with the 0.8m (F/15) telescope
located at the Observatoire de Haute Provence
Observatory (OHP), France.
Camera is an Andor 47-40 equiped by a R band filter.
We measured the magnitudes of the afterglow
described in Holland et al. (GCNC 3704):

Tmid (julian day) Exp (s)  R-Mag
2453582.35721     300      17.14 ± 0.10
2453582.36875     300      17.43 ± 0.09
2453582.37226     300      17.38 ± 0.09
2453582.37577     300      17.31 ± 0.06
2453582.37928     300      17.39 ± 0.09
2453582.38279     300      17.37 ± 0.11
2453582.38630     300      17.45 ± 0.13

Magnituded were computed as differential with
the three nearby USNO-B1 stars:
0862-0270612 R=14.96
0862-0270590 R=15.22
0861-0264205 R=15.35

These OHP data seems to show a flattening of the decay
(or a rebrightening) starting after the second exposure.

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