GCN Circular 8895
Subject
GRB 090205: VLT optical decay
Date
2009-02-07T09:35:05Z (15 years ago)
From
Paolo D'Avanzo at INAF-OAB <paolo.davanzo@brera.inaf.it>
P. D'Avanzo, D. Fugazza (INAF-OAB), V. D'Elia (INAF-OAR), R. Salvaterra,
C. C. Thoene (INAF-OAB), S. Piranomonte (INAF-OAR), S. Covino, S.
Campana (INAF-OAB), G. Chincarini (Univ. Bicocca) report, on behalf of
the MISTICI collaboration:
We continued monitoring GRB 090205 (Perri et al., GCN 8884) with the
ESO-VLT in imaging mode. Observations were carried out in R-band with
the FORS1 camera about 1.35 days after the burst.
Preliminary analysis of a first set of images (total exposure: 12 min)
reveals that the optical afterglow (D'Avanzo et al. GCN 8887; Kruehler &
Greiner GCN 8888) is still detected and that it faded by about 3 mags
with respect to our previous epoch of VLT observations (D'Avanzo et al.
GCN 8887). Assuming a power-law decy, the inferred decay index between
this two epochs is alpha ~ 1.8, steeper than what measured in the X-rays
at earlier epochs (Perri & Stratta, GCN 8891). Further optical
observations are ongoing.
We acknowledge the VLT staff for their support, in particular G. James
and L. Schmidtobreick.