[vsnet-grb-info 7537] GRB 090404: further NOT observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9095
SUBJECT: GRB 090404: further NOT observations
DATE:    09/04/05 18:51:36 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo at brera.inaf.it>

D. Malesani (DARK/NBI), P. D'Avanzo (Univ. Bicocca/INAF-Brera), P.
Jakobsson (Univ. Iceland), J.P.U. Fynbo (DARK/NBI), T. Liimets (Tartu Obs.
and NOT), and Z. Banhidi (Stockholm Obs.), report on behalf of a larger
collaboration:

Further to what reported in GCN 9093 (Malesani et al.), we observed again
the field of GRB 090404 (Ziaeepour et al., GCN 9086) with the NOT. The
object just outside the error circle noted in GCN 9093 is still well
detected in the R band. Comparison of the two epochs, taken with mean
times Apr 5.043 and Apr 5.214 UT (9.09 and 13.19 hr after the GRB,
respectively), reveals no fading of the object by more than 0.1 mag. This
corresponda to a limit on the decay index alpha < 0.25 (assuming F propto
t^-alpha).

The lack of significant variability and the location of the object outside
the XRT error circle make this object unlikely related to GRB 090404.

We acknowledge the NOT staff for excellent support.