[vsnet-grb-info 7910] GRB 090529: NOT optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9453
SUBJECT: GRB 090529: NOT optical observations
DATE:    09/05/30 23:53:10 GMT
FROM:    Giorgos Leloudas at Dark Cosmology Centre  <giorgos at dark-cosmology.dk>

G. Leloudas, D. Malesani, D. Xu, J.P.U. Fynbo (DARK/NBI), P.  
Jakobsson (Univ. Iceland),
M. E.  Brown (Caltech), E.L. Schaller (Univ. Hawaii) and T. Liimets  
(NOT & Tartu Obs.)
report on behalf of a larger collaboration:

We observed the field of GRB 090529 (Sakamoto et al., GCN 9430) with  
the Nordic Optical Telescope equipped with MOSCA.
3x600s R-band frames were obtained starting on May 30, 21:22 UT, 1.29  
days after the GRB.

The optical afterglow (Xin et al., GCN 9431; Schady et al., GCN 9435)  
is well detected in our images. Using the same reference star as in  
Kann et al. (GCN 9436), we obtain R=22.5 for the afterglow.

Comparison with the measurement by Kann et al., taken 0.3 days after  
the GRB, provides a decay index alpha = 0.72, assuming a power-law F 
(t) propto t^-alpha.