TITLE:   GCN CIRCULAR
NUMBER:  3809
SUBJECT: GRB050814: Fading red source
DATE:    05/08/15 08:36:17 GMT
FROM:    Brian Lindgren Jensen at U.of Copenhagen  <brian_j@astro.ku.dk>

Brian L. Jensen, Johan P. U. Fynbo, Jens Hjorth, Jesper Sollerman,
Jos? Mar?a Castro Cer?n, Kristian Pedersen, P?ll Jakobsson,
Darach Watson (DARK, NBI), Anna S. Arnadottir (U. of Lund, Sweden),
Diana A. Fiuza (U. of Helsinki, Finland) and
Jan-Erik Solheim (U. of Oslo, Norway) report:

"Using ALFOSC on the Nordic Optical Telescope we have obtained VRI
imaging of the field of GRB 050814.485 (Retter et al., GCN#3799)
on August 15.1, 2005 UT (~13.5 h after the burst).
In the refined XRT error-circle (Morris et al., GCN#3805) we clearly
detect the source reported by Bradly Cenko (GCN#3807) in our I- and
R-band images, whereas the source is absent in the V-band.

Based on preliminary photometry, we obtain for the source :

Date (UT)   Filter  Exptime Seeing  Mag
Aug 15.04   V       3x300s  1.1"    >23.0
Aug 15.06   R       3x300s  1.0"    23.2
Aug 15.07   I       3x300s  0.9"    20.5

Compared to the preliminary I-band detection reported in GCN#3807, the
source appears to be fading.
The colours of the object, if it is the afterglow of GRB 050814.485,
indicate either a high redshift (4.5<z<6.5) or significant
dust-reddening.

In addition, we detect a fainter, bluer source on the edge of the XRT
error-circle (at (RA,Dec)(J2000.0) = 17:36:44.93, +46:20:22.33).

An image of the field is shown at:

http://www.astro.ku.dk/~brian_j/grb/grb050814.485/ "

[GCN OPS NOTE(15aug05): Per author's request Arnadottir and Fiuza
were added to the author list.]