TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3439
SUBJECT: RBO Observations of GRB050520
DATE:    05/05/20 15:22:22 GMT
FROM:    Ron Canterna at U of Wyoming  <canterna@uwyo.edu>

D. Allen, C. Rodgers and R. Canterna report
on behalf of the RBO Team of the FUN GRB Collaboration:

We observed the position of the afterglow of GRB 050520
(Gotz et al., GCN 3430; Kennea et al., GCN 3434)
with the Red Buttes Obse rvatory 24-inch telescope
under semi-photometric conditions in VRI bands,
all 10 minutes exposures on  JD2453510.6.  Within a FOV 
of 8 arcmin of the Swift position (GCN 3434)
we do not detect the afterglow or no new source
down to the following limiting values:


UT      Start Time      Filter          Limiting
         Since GRB (hr)                  Magnitude
03:39   3:34            V               19.5
03:51   3:45            R               19.5
04:01   3:55            I               18.3
04:12   4:06            V               19.4
04:23   4:17            R               19.7
04:34   4:28            I               18.4
04:46   4:40            V               19.6
04:56   4:50            R               19.4
05:07   5:11            I               19.0
05:19   5:13            V               19.6
05:29   5:23            R               19.8
05:40   5:44            I               18.8

10 sigma limiting magnitudes were derived from the USNO-B1.0 catalogue and 
photometric transformations from Landolt standards.