[Message Prev][Message Next][Thread Prev][Thread Next][Message Index][Thread Index]

[vsnet-grb-info 451] GRB021004: Update Bisei photometric data



TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  1594
SUBJECT: GRB021004: Update Bisei photometric data
DATE:    02/10/07 09:06:45 GMT
FROM:    Yuji Urata at RIKEN  <urata@crab.riken.go.jp>

K. Matsumoto (Okayama Univ.), T. Kawabata (BAO), K. Ayani (BAO), 
Y.Urata (Titech / RIKEN), H. Yamaoka (Kyushu Univ.), 
N. Kawai (Titech / RIKEN) report:

"We have corrected our photometric data at Oct. 4 14:13 UT of the
GRB021004 afterglow (reported in GCN1567), which was obtained by using
the R-band photometric reference USNO star RA=00:26:58.77,
DEC=+18:56:56.1 as R=15.52 in the field photometry (Henden, GCN 1583),
and present the additional preliminary results as follows.

epoch  start time UT  exposure   R-mag.
1      Oct. 4 13:57   60s        16.38
2      Oct. 4 14:13   60s        16.36
3      Oct. 4 14:55   60s        16.63
4      Oct. 4 16:31   60s x 3    17.03

Their typical errors (1 sigma) are 0.12 mag.

We find that our point 1 is fainter than the magnitude extrapolated back
from the observations at later epochs (decay index 1.32, Weidinger et al.
GCN 1573).  This suggests that the break occurred during our
observations between 0.08 d and 0.2 d after the burst.

Analyses of the full data set of our time-resolved photometry in
VRI-bands are underway."

This message may be cited.

VSNET Home Page

Return to Daisaku Nogami


vsnet-adm@kusastro.kyoto-u.ac.jp