TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  1151
SUBJECT: GRB011121: fading behavior
DATE:    01/11/22 08:04:55 GMT
FROM:    Krzysztof Z. Stanek at CfA  <kstanek@cfa.harvard.edu>

K. Z. Stanek (Harvard-Smithsonian CfA), P. M. Garnavich (Notre Dame)
and Lukasz Wyrzykowski (Warsaw University Observatory) report:

Further R-band observations of the possible optical afterglow of the
GRB011121 carried out with the OGLE 1.3m telescope (+8kx8k OGLE-III
mosaic) 12.5 hours after the burst, indicate a fading behavior of the
new source at 11:34:30.38, -76:01:41.3 (J2000) reported by Wyrzykowski
et al. (GCN 1150):

HJD-2450000         UT           R_c       exp
2235.71890    011122 05:19  18.31+-0.03  200 sec
2235.80322    011122 07:20  18.64+-0.03  200 sec

Errors in the magnitudes are statistical only.  The R-band magnitudes
are relative to star "A" (11:34:18.9, -76:01:38.1, J2000), assuming
its magnitude R=17.4 (see GCN 1150).

Inspection of the Digitized Sky Survey shows a faint object 0.5" to
the northeast of the OT. The source, possibly the host galaxy has a
magnitude of approximately R=20.4 based on the assumed brightness of
star A.

We have also obtained BVI observations of the afterglow, reductions
of which are under way.

This message can be cited.