TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  2642
SUBJECT: GRB040812, optical/IR observations
DATE:    04/08/13 18:06:44 GMT
FROM:    Charles Bailyn at Yale/Astro  <bailyn@astro.yale.edu>

B. E. Cobb and C. D. Bailyn (Yale), part of the larger SMARTS 
consortium, report:

Using the ANDICAM instrument on the 1.3m telescope at CTIO, we
obtained optical/IR imaging of the error region of GRB 040812 
(Gotz et al. GCN 2640) beginning ~18.4 hours post-burst 
(2004-08-13 00:25 UT).  Optical imaging in B,V,R and I has a 
field of view of 6'x6' and, therefore, covers the entire GRB 
error circle.  IR imaging in J, H, K and Y has a smaller field 
of view and covers a region totalling 3 square arcminutes in 
the middle of the quoted error region.  Several dithered images 
were obtained in each filter, with total summed exposure times 
of 180s in each of BRIYJK and 120s in each of H and V.

Preliminary visual comparison of the optical images to the SDSS 
and the IR images to 2MASS frames does not reveal any new sources 
to the limit of the comparison frames.