TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  272
SUBJECT: GRB990308 (Trig. 7457), optical observations
DATE:    99/03/10 11:51:21 GMT
FROM:    Grant Williams at Clemson  <ggwilli@hubcap.clemson.edu>

G. Williams, H. Park and R. Porrata report on behalf of the LOTIS 
collaboration:

LOTIS and Super-LOTIS obtained early time observations 
of the error box of GRB 990308 (BATSE Trig. 7457).
This event was detected and localized by the 
XTE/All-Sky Monitor.  LOTIS began imaging the area 
centered on the 'Original' GCN coordinates 12.6 s after 
the start of the burst.  Five images (10 s integration) 
were obtained at these coordinates before the system 
received and responded to the 'Final' GCN coordinates. 
LOTIS began imaging the area centered on the 'Final' 
GCN coordinates 132.1 s after the start of the burst.  

The first five LOTIS images covered a small portion of 
the XTE/ASM error box within, but near the edge of the 
preliminary BATSE 3-sigma error circle.  We matched all 
stellar objects in the error box with known Guide Star 
Catalogue objects.  No transient sources brighter than 
m ~ 11.5 (no filter) were detected.  Wispy high clouds 
reduced the system's limiting magnitude during this event.

LOTIS slewed to the more accurate 'Final' GCN coordinates 
132.1 s after the start of the burst. The subsequent images 
covered the entire XTE/ASM error box within the 
BATSE 2-sigma error circle.  We found a single anomalous 
constant source within the error box with a position which 
corresponds to the position of a V ~ 10.6 asteroid (Laetitia)
at the time of the image.  All other sources within the 
XTE/ASM error box correspond to known stars in the GSC.
No fading or flaring objects brighter than m ~ 11.0 were 
found.

In addition, Super-LOTIS (60 cm reflector) began a raster 
scan around the 'LOCBURST' GCN coordinates 1700 s after 
the start of the burst. Four Super-LOTIS images 
(30 s integration; t=1694 s, 1809 s, 2620 s, 3923 s)
covered most of the XTE/ASM error box within the BATSE 2-sigma 
error circle.  No fading or flaring objects brighter than 
m ~ 14.0 (no filter) were detected in the Super-LOTIS images.
Super-LOTIS is presently operating at a temporary site 
at LLNL utilizing an uncooled prototype CCD camera. 
Thin clouds and surrounding building lights prevented 
the system from reaching a deeper limiting magnitude.

Further details of the LOTIS timing and coverage as well 
as images are posted at: 

http://hubcap.clemson.edu/~ggwilli/LOTIS/GRB990308.html

This message is citable.