TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  599
SUBJECT: GRB000301C, optical R-band observations
DATE:    00/03/08 15:20:28 GMT
FROM:    Nicola Masetti at ITeSRE,CNR,Bologna  <masetti@tesre.bo.cnr.it>

S. Bernabei (Astron. Obs., Bologna), C. Bartolini, L. Di Fabrizio, 
A. Guarnieri, A. Piccioni (Dip. Astronomia, Univ. of Bologna), 
and N. Masetti (ITeSRE/CNR, Bologna) report: 

"We have imaged the proposed optical counterpart (GCN #570) of GRB000301C
(GCN #568) on March 3, 4, 6, 7 and 8, 2000, in the R band with the 152 cm
Loiano telescope (plus EEV CCD) of the Observatory of Bologna. 

Using the R magnitudes of the four comparison stars quoted by Garnavich
et al. (GCN #574) we obtain the following figures:

               Date        exptime    seeing        R mag.
           ---------------------------------------------------
            Mar. 3.191     1000 s      2".0     20.11 +- 0.05
            Mar. 4.178     2200 s      3".0     20.22 +- 0.2
            Mar. 6.145     1800 s      1".7     21.60 +- 0.2
            Mar. 7.135     1800 s      1".7     21.63 +- 0.15
            Mar. 8.157     1800 s      1".5     21.63 +- 0.1

The R magnitudes of the first two days, albeit the measurement of March 4
was acquired under bad weather conditions (thick cirrus), seem to confirm
the deviations of the decay of this object from the typical power-law
trend seen in GRB afterglows, as already pointed out by other authors (see
GCN #581 and #586). 

The present data also agree with the result reported by Boer & Veillet
(GCN #598) and indicate a "standstill" of the optical candidate. Thus,
either we are already seeing the host galaxy of this GRB (in this case it
would not be the object at 1" W, 2" N of the transient; see GCN #592,
#594, #598), or the optical transient associated to GRB000301C has a
definitely peculiar behaviour, or this is not the optical counterpart of
GRB000301C.

We also obtained B and I images which are now entering the reduction
stage.


This message is quotable.".