[vsnet-grb-info 6139] GRB 080523: VLT optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7770
SUBJECT: GRB 080523: VLT optical observations
DATE:    08/05/24 14:32:01 GMT
FROM:    Daniele Malesani at Niels Bohr Inst,Dark Cosmology Center  <malesani at astro.ku.dk>

Johan P. U. Fynbo, Daniele Malesani (DARK), Pall Jakobsson (Univ. 
Hertfordshire), Bo Milvang-Jensen and Jens Hjorth (DARK), report on 
behalf of a larger collaboration:

We observed the field of GRB 080523 (Stroh et al., GCN 7767) with the 
ESO VLT equipped with FORS2. Photometric observations were conducted on 
2008 May 24, between 8:14 and 8:27 UT (about 10.9 hr after the GRB). 
Inside the revised XRT error circle (Osborne et al., GCN 7768), we 
detect a faint source at coordinates (J2000):

RA = 01:23:11.61
Dec = -64:01:51.8

Lacking any information on variability, we cannot assess whether this 
source is associated with GRB 080523.

A spectrum of the object shows detection of continuum in the blue down 
to 4200 AA, implying a redshift limit z < 2.5. Further analysis is underway.

We note the presence of two further, faint sources close to, but 
slightly outside of, the refined XRT error circle at (RA, Dec) = 
(01:23:11.21, -64:01:53.9) and (01:23:10.88, -64:01:50.4).

We acknowledge excellent support and positive initative from the ESO 
observing staff, particularly Yuri Beletsky and Patricia Guajardo.