TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  2160
SUBJECT: GRB030329, optical observation
DATE:    03/04/21 22:46:18 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

M.A. Ibrahimov, I.M. Asfandiyarov, B.B. Kahharov (Ulugh Beg Astronomical
Institute of the Uzbek Academy of Sciences), A.Pozanenko (IKI), V.Rumyantsev
(CrAO), G.Beskin (SAO)  on behalf of large collaboration report:

We have observed the OT GRB030329 found by B.Peterson and P.Price (GCN 1985)
using 1.5m telescope of Mt.Maidanak High-altitude Observatory.    Several
BVRI Bessel images were obtained on April, 7,9,10 and 20. The seeing on
Apr.7 was in range of 1-1.5 arcsec, on Apr.10 - 0.9-1 arcsec for R and in
1-1.3 arcsec for B. In Apr. 9 the weather was unfavorable and some images
were obtained trough clouds.  Based on filed photometry still by A. Henden
(GCN 2023) we estimate the OT magnitudes:

Mid time
UT, Apr. exposure filter mag    err

 7.7819  7x600    B      19.78  0.04
 7.7986  5x600    V      19.20  0.03
 7.7771  8x600    R      18.84  0.03
 7.8160  3x600    I      18.44  0.06
 9.7653  2x600    B      20.07  0.14
 9.7813  2x600    V      19.37  0.08
 9.7729  4x600    R      19.10  0.06
10.7625  6x600    B      19.96  0.08
10.7792  6x600    V      19.56  0.06
10.7354  6x600    R      19.29  0.07
10.7792  4x600    I      19.11  0.08

And  preliminary reduction of measurements on Apr.20 is following

UT, Apr. exposure filter mag

20.6444  2x600    R      19.92
20.6604  2x600    B      21.08

With typical error of 0.15 (B) and 0.13 (R)

Our measurements on Apr. 10 are consistent with TNG observation by V. Testa
et al. (GCN 2141).   While in Apr. 7 - 10 the brightness of OT  is
consistent with slow fading, we could not detect brightness change in R
(within our accuracy) between observation on Apr.14 (GCN 2141) and our
measurement on Apr. 20.