TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3104
SUBJECT: GRB 050315, SMARTS optical/IR afterglow observations
DATE:    05/03/16 22:18:02 GMT
FROM:    Bethany Cobb at Yale U  <cobb@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 050315
(GCN 3094, Parsons et al.) beginning ~11.6 hours post-burst
(2005-03-16 08:35:09 UT).  Total summed exposure times amounted
to 180s in BRIYJK and 120s in H and V.

An optical source is detected in R and I at the coordinates of the 
reported optical afterglow candidate (GCN 3100, Kelson & Berger).  This 
source is, however, only slightly brighter than our detection limits.  
Preliminary comparison with Landolt Standard PG 1047+003 and USNO B1.0 
stars yields the following approximate afterglow magnitudes:

         R = 20.9
         I = 20.3

No source was detected in B or V with upper limits of B > 22.3 and V > 21.4.

Additionally, the afterglow candidate is not detected in the IR images to 
the following detection limits (obtained by comparison with 2MASS):

         J > 18.0
         H > 17.4
         K > 16.3