[vsnet-grb-info 3349] GRB060502b: optical observations

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  5184
SUBJECT: GRB060502b: optical observations
DATE:    06/05/29 10:02:37 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

V.Rumyantsev (CrAO),  R. Karimov (MAO),  R. Salyamov (MAO),  E. Pavlenko
(CrAO), Yu. Efimov (CrAO), A. Pozanenko (IKI),  M. Ibrahimov (MAO) on behalf
of larger GRB follow up collaboration report:

We observed the location of Swift short GRB060502B (Troja et al., GCNs 5055,
5059, 5063, 5093) in the R band with 1.5m telescope of Maidanak Astronomical
Observatory (MAO)  starting on May 02 22:43 (UT) (5.3 hours after the
trigger) and Shajn 2.6m telescope of CrAO between  May 03 (UT) 01:27 - 02:41
(8.6 hours after the trigger). Totally we obtained 6 images of 180 sec
exposure with mean seeing ~0.95" in Maidanak 1.5m and 39 images of 60 sec
exposure in CrAO observatory (seeing ~3").  In  combined images we detect G1
galaxy mentioned by Berger et al. (GCN 5071) and  Halpern et al. (GCN 5072)
and do not detect S2 source (Price et al. GCN 5077). A photometry of G1 and
S1 sources is based on  USNO B1.0 star R=17.5 mag (USNO-B1 426-035230 RA,
Dec = 278.92572,52.61611):

Mid time    Telescope   Exp.   G1           S1           Limiting   (UT)
                        sec    mag          mag          mag

May 02.954  MAO 1.5m   6È180  ~24.2        21.40 +/-0.10   23.6
May 03.086  CrAO 2.6m  39x60  23.7 +/-0.3  21.65 +/-0.05   24.1

Our brightness estimation of G1 is consistent with brightness estimations
obtained in  MDM 1.3 (T0+15 h) R~23.9  (Halpern et al. GCN5072) and in
Gemini North (T0+17 h) R~23.8 (Price et al. GCN5077).

The combined images can be found in http://grb.rssi.ru/GRB060502b
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