TITLE:   GCN CIRCULAR
NUMBER:  2250
SUBJECT: GRB 030416: Optical Observations
DATE:    03/05/27 15:19:05 GMT
FROM:    Jane Moran at U.North Carolina  <moranj@physics.unc.edu>

A. Henden, J. Silvay, J. Moran, R. Soule, D. Reichart, J. Schaefer, R.
Canterna, and B. Scoggins report on behalf of the USNO, UWYO, and UNC GRB
teams of the FUN GRB collaboration:

We observed the entire 14 arcminute diameter error circle of XRF 030416
(Jernigan et al., GCN 2209) in BVRcIc beginning 15.4 hours after the burst,
despite a bright moon.  We report the following limiting magnitudes:

Start      Start Time Filter Integration Limiting  Telescope  Calibration
Date       Since GRB         Time (sec)  Magnitude            Catalog
           (hours)           x Pointings (3 sigma)
Apr 17.103 15.391     Rc     6000 x 1    19.8      0.6-m RBO* USNO A2.0
Apr 17.143 16.361     B      300 x 1     20.1      1.3-m USNO USNO A2.0
Apr 17.149 16.502     V      300 x 1     20.9      1.3-m USNO ACT
Apr 17.155 16.643     Rc     300 x 1     20.4      1.3-m USNO USNO A2.0
Apr 17.160 16.784     Ic     300 x 1     19.9      1.3-m USNO USNO B1.0
Apr 20.143 88.454     Rc     2160 x 1    22.3      1.3-m USNO USNO A2.0

* RBO = Red Buttes Observatory

Using the image subtraction routine ISIS2 (Alard 2000, A&AS, 114, 363), we
find no transient sources in either of our Rc images of April 17th when
compared to our Rc image of April 20th.