[vsnet-grb-info 3238] GRB 060502B: AROMA refined photometric calibration

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  5073
SUBJECT: GRB 060502B: AROMA refined photometric calibration
DATE:    06/05/04 19:15:10 GMT
FROM:    Kazutaka Yamaoka at Aoyama Gakuin U  <yamaoka at phys.aoyama.ac.jp>

I.Takahashi, T.Uehara, K.Yoshida, A.Kobayashi,
T.Koshiishi, K.Tanaka, Y.E.Nakagawa, S.Sugita, K.Yamaoka,
A.Yoshida (AGU) report:

After the previous report (GCN 5065), we carried out
further photometric calibrations for the observations
of the GRB 060502B field (Troja et al. GCN 5055, GCN 5059).
We have taken 100 frames of R band image with 20s exposure
each and photometric calibration was mede by every 20 frames
by comparing with USNO A2.0 stars in the same field.
The 3 sigma limiting magnitude of each combined image
is as below.

data set  mean time     time - burst[s]  lim-mag R (3sigma)
======================================================
1st       17:30:00 UT   319              16.12 +/-0.16
2nd       17:37:35 UT   774              16.26 +/-0.19
3rd       17:45:13 UT   1232             16.00 +/-0.05
4th       17:52:44 UT   1683             16.00 +/-0.02
5th       18:00:13 UT   2132             16.30 +/-0.02