TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  5094
SUBJECT: GRB060507: optical afterglow detection
DATE:    06/05/09 13:17:15 GMT
FROM:    Christina Thoene at Niels Bohr Institute,DARK Cosmo Ctr  <cthoene@astro.ku.dk>

Christina C. Thoene, Brian L. Jensen, Johan Fynbo (Dark Cosmology Centre),
Jan-Erik Solheim (University of Oslo), and Erika Pakstiene
(TFAI, University of Vilnius) report

We observed the field of GRB060507 (GCN 5084) in the I-band with the NOT
and ALFOSC on La Palma, starting at May 7th, UT 03:08:19 (1.13h after the
burst) at high airmass. On the edge of the XRT revised error circle (99%
confidence) (GCN 5087) we detect a new source at the position (J2000)

RA = 05:59:50.52
Dec = +75:14:55.9

The preliminary I-band magnitude obtained from 3x300s stacked images with
a mean time of 1.3h after the burst is

I = 19.1 +- 0.1
(compared to four nearby USNO stars)

5x300 I-band images from May 9th show that the source is transient and
therefore likely to be the afterglow of GRB060507

A finding chart is available at:
http://www.astro.ku.dk/~brian_j/grb/grb060507.079/

[GCN OPS NOTE(10may06): Per author's request, the E.P. author was added.]