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GCN Circular 536

GRB000201 Optical Observations
2000-02-09T03:34:54Z (24 years ago)
Robert Kehoe at U.Michigan/ROTSE <>
R. Kehoe (Univ. of Michigan), J. Wren, R. Balsano (Los Alamos) and 
B. Lee (Fermilab) report on behalf of the ROTSE collaboration (U.

We have observed the error box of GRB000201 provided by the Final and
LocBurst Position Notices dated 1-Feb-00 using the ROTSE-I telephoto
camera array.  The initial BACODINE Notice localization fell below our
elevation cut and was not observed.  The ROTSE-I trigger protocol for  
Final Notices begins with 20 second exposures for the first few frames
followed by 80 second exposures thereafter.  All LocBurst response images
are 80 second exposures.  We have searched the LocBurst 1 sigma error
region in the first half hour of observations and found no significantly
varying objects.  We have also searched all images at the location of
the optical transient described in GCN #535 at RA = 139.03667, DEC =
18.10361 (J2000).  For the nine LocBurst observations, this position falls
in the overlap region between cameras 'a' and 'd', giving a degree of
redundancy.  The times and sensitivities (5 sigma cut-off) of these
observations are:

         observation #   time - T0 (s)   limiting magnitude
         -------------   -------------   ------------------
         1-7             85.9 to 322             14.1
         8-16            329 to 634              14.3
         17-41           641 to 3055             15.1
	 38-41 co-add	 2689 to 3055		 15.8

No object is detected at the transient location in any image in any camera.  
To further explore the possibility of a dim counterpart, we have co-added
the last four LocBurst images (see Table).  No object is detected at the 
transient location in this image.  Given our observation that any source
at this location is around mag. 16 or dimmer within 5 minutes of the TAROT
position, we believe this is not the optical counterpart to GRB000201.
Further analysis to explore the wider field is in progress.

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