[vsnet-grb-info 3715] GRB 060904B : CFHT/WIRCam NIR afterglow observations

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  5549
SUBJECT: GRB 060904B : CFHT/WIRCam NIR afterglow observations
DATE:    06/09/08 11:56:31 GMT
FROM:    Yuji Urata at Saitama U  <urata at crystal.heal.phy.saitama-u.ac.jp>

K.Y. Huang, W.H. Ip, Y.S. Lee (NCU) and Y. Urata (Saitama Univ.)
on behalf of EAFON report:

"The NIR afterglow observations of GRB 060904B (Grup et al.; Rykoff et
al; Fugazza et al.) with CFHT/WICam started from 9.40 hours after the
GRB occurred. Our J and Ks images show the magnitude of the afterglow
are J~ 19 at 10.8 hours and Ks~ 17 at 9.4 hours (compare with 2MASS
stars).

  Refer to the SMART observations (Cobb et al., GCN 5515), our J band
result indicates the decay rate (Flux ~ t^alpha) may change form ~-
0.65 to ~ -1.37. However, we do not find the decay rate change from
our Ks band results.

We would like to thank CFHT/WIRCam staff, especially A. Loic and
P. Martin for their assistance.

This message may be cited."