TITLE:   GCN CIRCULAR
NUMBER:  7802
SUBJECT: GRB 080604: Early Super-LOTIS Observations
DATE:    08/06/04 09:32:05 GMT
FROM:    Grant Williams at Steward Observatory  <ggwilli@gmail.com>

G. G. Williams (MMTO), P. A. Milne (Steward Observatory) and A. Updike
(Clemson) on behalf of the Super-LOTIS Collaboration, report:

The robotic 0.6-m Super-LOTIS telescope began observing the error box
of GRB 080604 (Swift Trigger 313116, La Parola et al. GCN 7800) at
07:28:59.0 UT, 118 seconds after the trigger.  Our initial
observations include 5 x 10s exposures, 5 x 20s exposures, and 30 x
60s exposures, all in the R-band.

We do not detect the afterglow reported by La Parola et al. (GCN 7800)
and confirmed by Rol et al. (GCN 7801) in our earliest exposure to the
following 5-sigma limiting magnitude determined using the nearby
USNO-B1.0 star 1105-0256520 at RA=15:47:45.32, Dec=+20:33:38.4 with
R2mag=14.56:

t_start (UT)	exp t (s)	t_start-t_0 (s)	Limit
--------------------------------------------------------
07:28:59.0	10 		118.0 		R > 17.5

We also do not detect the afterglow in our later images or the sum of
our 20s images and 6x60s images.  Additional observations and analysis
are ongoing.