[vsnet-grb-info 8989] GRB 100305A: Gemini z -band observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  10478
SUBJECT: GRB 100305A: Gemini z'-band observation
DATE:    10/03/05 19:56:11 GMT
FROM:    Antonino Cucchiara at PSU  <cucchiara at astro.psu.edu>

A. Cucchiara (PSU), report on behalf of a larger collaboration:

"We continued our observations of GRB 100305A with the Gemini-N
telescope mounted with the GMOS camera.
A sequence of z'-band images has been taken for a total exposure
time of 15 min.

No clear object is visible in the position of the optical afterglow
previously reported (GCN 10473) at the following 3-sigma upper limit:

z' > 23.42 mag

We also report a corrected error measure in our photometry.
The correct magnitude estimates at T0 + 2h are:

r' = 23.95 +- 0.30 mag
i' = 23.71 +- 0.06 mag

We apologize for any inconvenience this may have caused."